[Review] Refactor ConfigContainer to use dask config

[ayushdg]

This PR removes ConfigContainer and utilities to modify them as added in #286 in favor of using upstream Dask's config module and the flexibility it provides.

Key Changes:

• Config options are no longer schema specific. Users can either modify/provide a set of configurations that apply globally across all operations or specify config options on a per query basis.
• The keywords used for different configuration options are being renamed to be more in line with the dask config pattern. All config options for dask-sql start with the prefix sql.
  • eg: dask.groupby.aggregate.split_out renamed to sql.groupby.split_out

Functionality Enabled:

• Users can provide dask-sql configurations in yaml files, as environment variables or any other way dask supports and will become a part of the global dask config which can be consumed by any Dask-project that uses dask.config.
• Users can specify configuration options on a per-query basis by using context.sql({"query_string"},config_options={options}).

Checklist:

• Add new config features
• Remove the usage of ConfigContainer in favor of dask_sql.config
• Add tests for config
• Update setup to ensure the yaml files are packaged properly

[codecov-commenter]

Codecov Report

Merging #392 (58eada8) into main (eee8c65) will increase coverage by 0.23%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #392      +/-   ##
==========================================
+ Coverage   88.94%   89.17%   +0.23%     
==========================================
  Files          68       69       +1     
  Lines        3337     3327      -10     
  Branches      657      654       -3     
==========================================
- Hits         2968     2967       -1     
+ Misses        297      287      -10     
- Partials       72       73       +1     

Impacted Files	Coverage Δ
dask_sql/datacontainer.py	96.96% <ø> (+3.16%)	⬆️
dask_sql/__init__.py	100.00% <100.00%> (ø)
dask_sql/config.py	100.00% <100.00%> (ø)
dask_sql/context.py	100.00% <100.00%> (ø)
dask_sql/physical/rel/logical/aggregate.py	94.77% <100.00%> (-0.04%)	⬇️
dask_sql/_version.py	34.00% <0.00%> (+1.44%)	⬆️

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[charlesbluca]

This is really nice 🙂 especially like the configuration reference page in the docs; just some questions related to the handling of Context.set_config and then I think this should be good to merge.

Also going to merge in the latest changes from #406 to see if that resolves the API reference issues in the docs build for this PR.

[ayushdg]

@charlesbluca Should be ready for another round of reviews.

[charlesbluca]

LGTM; thanks for the work here @ayushdg 😄