Feature/59/image upload

[M1niplayer]

closes #59

Adding functionality for including images in posts which is to display in chapter website, discord, RSS feeds

features:

• do some frontend stuff to get some drag n drop action when making a post (and for that matter events)
• upload image to AWS bucket, which enables saving the URL to the calypso db, URL is then used to display image (wow!)
• alt text

notes:

• uploaded images files can only be at most 2MB, be 1920x1080 image resolution, of the file type {png, jpg} and the filename extension should match whatever MIME file type Tika reads from the magic bytes (and also, your file should be an image).
• there is a double save in the edit controller. One to get the postid, which is then used to compose the URL 🥴

what still has to be done after this:

• show image on bawang and discord bot
• do the same thing for activities

useful image:

[M1niplayer]

i don't even know myself

[M1niplayer]

calypso/src/main/java/se/datasektionen/calypso/controllers/admin/EditController.java

Lines 42 to 52 in 6b60f98

	@GetMapping("/admin/duplicate")
	public String duplicateForm(@RequestParam(name = "id") Long id, Authentication auth, Model model) {
	var user = (DAuthUserDetails) auth.getPrincipal();
	var baseItem = itemRepository.findById(id).orElseThrow(ResourceNotFoundException::new);
	if (baseItem == null)
	throw new ResourceNotFoundException();
	var item = baseItem.duplicate();
	item.setAuthor(user.getUser());

nvm