feat: Implement option to enable / disable sync of declined events

[alxndr13]

• fmt: make the linter happy and add document starts to yamls
• feat: add Accepted field to models.Event
• feat(outlook): add ResponseStatus field and map to models.Event.Accepted
• feat(google): check for Event Response and map to models.Event.Accepted
• feat: add sync_declined_events field to config
• feat: add SyncDeclinedEvents field to controller struct
• test: modify tests for the newly introduced accepted field and controller property
• feat: add function to remove declined events if config parameter is set
• docs: add sync_declined_fields parameter to readme.md

[MichaelEischer]

I'm wondering whether it would be cleaner to implement the removal of declined events using an extended variant of the transformers. That way the filter/transform steps and the actual synchronization remain cleanly separated.

[alxndr13]

I'm wondering whether it would be cleaner to implement the removal of declined events using an extended variant of the transformers. That way the filter/transform steps and the actual synchronization remain cleanly separated.

Good idea. Approaching it like this we could also create the base for #65

[alxndr13]

I'm wondering whether it would be cleaner to implement the removal of declined events using an extended variant of the transformers. That way the filter/transform steps and the actual synchronization remain cleanly separated.

@MichaelEischer i just pushed some new commits which introduced filters, analogue to the transformers we already have. Let me know what you think!

Not polished, just works. there's a lot of potential for deduplication of code here and there and better error handling.

edit: tests aren't working as well 😅

[MichaelEischer]

I like the approach in general.

Initially, I've wondered whether it might be easier to have a merged TransformerFilter, but that is far less clean than the proper separation between Transformer and Filter. And we likely don't need to potentially increased expressiveness of such a combined construct.

[MichaelEischer]

I've added a small cleanup for the readme.