refactor!: Update the crawlers & storage clients structure (#828)

## Description

Update the dir structure of crawlers & storage clients, as discussed
earlier on the Slack.

I decided to export nothing on the 2nd level because of the extras & it
would also be pretty huge (taking into account we have also models
there).

E.g. for BS crawler:
```diff
- from crawlee.beautifulsoup_crawler import BeautifulSoupCrawler, BeautifulSoupCrawlingContext
+ from crawlee.crawlers import BeautifulSoupCrawler, BeautifulSoupCrawlingContext
```

Or for memory storage client:
```diff
- from memory_storage_client import MemoryStorageClient
+ from storage_clients import MemoryStorageClient
```

This should be generally more aligned with the concepts of Crawlee. Of
course, quite a breaking change though. Better to do it now than later.

This will not be applied to the JS version because sub-pkgs like
`PlaywrightCrawler` are its own package.

## Issue

- Closes: #764

## Breaking changes

### Crawlers & CrawlingContexts

- All crawler and crawling context classes have been consolidated into a
single sub-package called `crawlers`.
- The affected classes include: `AbstractHttpCrawler`,
`AbstractHttpParser`, `BasicCrawler`, `BasicCrawlerOptions`,
`BasicCrawlingContext`, `BeautifulSoupCrawler`,
`BeautifulSoupCrawlingContext`, `BeautifulSoupParserType`,
`ContextPipeline`, `HttpCrawler`, `HttpCrawlerOptions`,
`HttpCrawlingContext`, `HttpCrawlingResult`,
`ParsedHttpCrawlingContext`, `ParselCrawler`, `ParselCrawlingContext`,
`PlaywrightCrawler`, `PlaywrightCrawlingContext`,
`PlaywrightPreNavCrawlingContext`.

Example update:
```diff
- from crawlee.beautifulsoup_crawler import BeautifulSoupCrawler, BeautifulSoupCrawlingContext
+ from crawlee.crawlers import BeautifulSoupCrawler, BeautifulSoupCrawlingContext
```

### Storage clients

- All storage client classes have been moved into a single sub-package
called `storage_clients`.
- The affected classes include: `MemoryStorageClient`,
`BaseStorageClient`.

Example update:
```diff
- from crawlee.memory_storage_client import MemoryStorageClient
+ from crawlee.storage_clients import MemoryStorageClient
```

### CurlImpersonateHttpClient

- The `CurlImpersonateHttpClient` changed its import location.

Example update:
```diff
- from crawlee.http_clients.curl_impersonate import CurlImpersonateHttpClient
+ from crawlee.http_clients import CurlImpersonateHttpClient
```

Author: vdusek

docs/deployment/code/apify/crawler_as_actor_example.py

@@ -1,6 +1,6 @@
 from apify import Actor
 
-from crawlee.beautifulsoup_crawler import BeautifulSoupCrawler, BeautifulSoupCrawlingContext
+from crawlee.crawlers import BeautifulSoupCrawler, BeautifulSoupCrawlingContext
 
 
 async def main() -> None:

docs/examples/code/add_data_to_dataset_bs.py

@@ -1,6 +1,6 @@
 import asyncio
 
-from crawlee.beautifulsoup_crawler import BeautifulSoupCrawler, BeautifulSoupCrawlingContext
+from crawlee.crawlers import BeautifulSoupCrawler, BeautifulSoupCrawlingContext
 
 
 async def main() -> None:

docs/examples/code/add_data_to_dataset_pw.py

@@ -1,6 +1,6 @@
 import asyncio
 
-from crawlee.playwright_crawler import PlaywrightCrawler, PlaywrightCrawlingContext
+from crawlee.crawlers import PlaywrightCrawler, PlaywrightCrawlingContext
 
 
 async def main() -> None:

docs/examples/code/beautifulsoup_crawler.py

@@ -1,8 +1,7 @@
 import asyncio
 from datetime import timedelta
 
-from crawlee.basic_crawler import BasicCrawlingContext
-from crawlee.beautifulsoup_crawler import BeautifulSoupCrawler, BeautifulSoupCrawlingContext
+from crawlee.crawlers import BasicCrawlingContext, BeautifulSoupCrawler, BeautifulSoupCrawlingContext
 
 
 async def main() -> None:

docs/examples/code/beautifulsoup_crawler_stop.py

@@ -1,6 +1,6 @@
 import asyncio
 
-from crawlee.beautifulsoup_crawler import BeautifulSoupCrawler, BeautifulSoupCrawlingContext
+from crawlee.crawlers import BeautifulSoupCrawler, BeautifulSoupCrawlingContext
 
 
 async def main() -> None:

docs/examples/code/capture_screenshot_using_playwright.py

@@ -1,6 +1,6 @@
 import asyncio
 
-from crawlee.playwright_crawler import PlaywrightCrawler, PlaywrightCrawlingContext
+from crawlee.crawlers import PlaywrightCrawler, PlaywrightCrawlingContext
 from crawlee.storages import KeyValueStore
 
 

docs/examples/code/crawl_all_links_on_website_bs.py

@@ -1,6 +1,6 @@
 import asyncio
 
-from crawlee.beautifulsoup_crawler import BeautifulSoupCrawler, BeautifulSoupCrawlingContext
+from crawlee.crawlers import BeautifulSoupCrawler, BeautifulSoupCrawlingContext
 
 
 async def main() -> None:

docs/examples/code/crawl_all_links_on_website_pw.py

@@ -1,6 +1,6 @@
 import asyncio
 
-from crawlee.playwright_crawler import PlaywrightCrawler, PlaywrightCrawlingContext
+from crawlee.crawlers import PlaywrightCrawler, PlaywrightCrawlingContext
 
 
 async def main() -> None:

docs/examples/code/crawl_multiple_urls_bs.py

@@ -1,6 +1,6 @@
 import asyncio
 
-from crawlee.beautifulsoup_crawler import BeautifulSoupCrawler, BeautifulSoupCrawlingContext
+from crawlee.crawlers import BeautifulSoupCrawler, BeautifulSoupCrawlingContext
 
 
 async def main() -> None:

docs/examples/code/crawl_multiple_urls_pw.py

@@ -1,6 +1,6 @@
 import asyncio
 
-from crawlee.playwright_crawler import PlaywrightCrawler, PlaywrightCrawlingContext
+from crawlee.crawlers import PlaywrightCrawler, PlaywrightCrawlingContext
 
 
 async def main() -> None: