[performance] filter model and database table improvements (#4277)

- removes unnecessary fields / columns (created_at, updated_at)
- replaces filter.context_* columns with singular filter.contexts bit field which should save both struct memory and database space
- replaces filter.action string with integer enum type which should save both struct memory and database space
- adds links from filter to filter_* tables with Filter{}.KeywordIDs and Filter{}.StatusIDs fields (this also means we now have those ID slices cached, which reduces some lookups)
- removes account_id fields from filter_* tables, since there's a more direct connection between filter and filter_* tables, and filter.account_id already exists
- refactors a bunch of the filter processor logic to save on code repetition, factor in the above changes, fix a few bugs with missed error returns and bring it more in-line with some of our newer code

Reviewed-on: https://codeberg.org/superseriousbusiness/gotosocial/pulls/4277
Co-authored-by: kim <grufwub@gmail.com>
Co-committed-by: kim <grufwub@gmail.com>

internal/processing/timeline/home.go

@@ -22,7 +22,6 @@ import (
 	"net/url"
 
 	apimodel "code.superseriousbusiness.org/gotosocial/internal/api/model"
-	statusfilter "code.superseriousbusiness.org/gotosocial/internal/filter/status"
 	"code.superseriousbusiness.org/gotosocial/internal/gtserror"
 	"code.superseriousbusiness.org/gotosocial/internal/gtsmodel"
 	"code.superseriousbusiness.org/gotosocial/internal/log"
@@ -77,7 +76,7 @@ func (p *Processor) HomeTimelineGet(
 		pageQuery,
 
 		// Status filter context.
-		statusfilter.FilterContextHome,
+		gtsmodel.FilterContextHome,
 
 		// Database load function.
 		func(pg *paging.Page) (statuses []*gtsmodel.Status, err error) {