This PR adds two methods to the presentation compiler interface so that adding new code actions will be easier.
The functions are:

• public CompletableFuture<List<TextEdit>> codeAction(OffsetParams params, String codeActionId, Object codeActionPayload)
• public List<CodeActionId> supportedCodeActions()

codeAction is supposed to be a common method for executing code actions with the presentation compiler.

supportedCodeActions is a new method that is supposed to allow better handling for code actions that are implemented for only some presentation compilers e.g. only for Scala 3. (Here might be some discussion around whether we can allow some more information to be passed to this functions, so that the result will depend on e.g. the location in the file in addition to the presentation compiler used for the file).

When creating a new code action that needs a new presentation compiler method that fits this interface -- only returns List<TextEdit> the new steps will be:

• when implementing the code action handler class (the one that extends CodeAction) override its val maybeCodeActionId: Option[String] with Some("TheNewCodeActionIdYouCreated")
• in your presentation compiler implementation add a new case for your new CodeActionId and handle the code action there.
• if necessary, create a new class for the code action payload in the shared java sources (try to avoid doing so, since this would also have to be backported to the other presentation compiler implementation (metals -> scala3 or scala3 -> metals)

closes #6265