[Tracking] Add more filters

[wschella]

On the current data, we can definitely provide some extra filters that are useful.
These all deserve their own issue, some are more niche then others, some definitely are more difficult:

• Data-filter: Filter agendapunten on their date. Hard cause there's actually only a date for the zitting, and there is both a planned date, and an actual date. Often, one is also missing (mostly actual date), which can intentional (just did not happen yet) or not. Probably requires some new mu-search features.
• Is-public-filter: Filter agendapunten that are public or not public. Quite important, but difficult to get right because there is both agendaItem.isPlannedPublic and agendaItemHandling.isPublic, and mu-search doesn't quite support boolean queries yet.
• Provincie, Bestuursorgaan-type, Bestuurseenheid-type: Some <select>-type filters for specific things. Provincie might be difficult because of the data (will require some augmentation likely), the others might be too niche (but I imagine it's also useful to only select OCMW's, externe organen, or burgemeester or smth).
• Approved/declined-points: Filter on whether the agenda item got voted for, or voted against, or even if just a vote happened.
• People-filter: Filter on involved people, can be very useful to check on a politician! Mostly in the stemming, who proposed the item, and who lead the session, but I'm not sure whether the data supports the latter ones.
• Legal-type-filter: Filter on the legal type of the resulting besluit (e.g. verkeersregelement or smth). The data supports some notion of this.
• Fuzzy search setting: Users should be able to select whether they want to match exact keywords, or match more fuzzily (or even phrases). Fuzzy could also be the default, and searching exact a flag. At least some information should be provided to the user on how it works, since :sqs: also provides some options such as OR or quotes around the term.
• Inverse has-relation-filter: Currently it's an option to search for items having a certain attribute, it would be useful for ABB to search for agendapoints missing an attribute (so they can request corrections). The hardest part here is UX. Quite niche.
• Search-in-field setting: Currently all fields are being searched, users might not care about some of them, or explicitly only search in 1 field (e.g. besluit motivatie).