feat(filters): split into two stages (base, detailed) to reduce api calls

[setchy]

Partially addresses #1997

Splits the notification filtering into a two-stage process

• Base notification filters (type and reason)
• Detailed notification filters (user type, handles, state)

This helps reduce detail enrichment api calls in certain circumstances.

[setchy]

@grahamj - this is part one of reducing api calls - hope you find it useful.

I'll follow-up with a separate to avoid fetching reviews etc if notifications have been filtered by their detailed state

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

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