Fixed some issues with muting

• Restructured muting logic to be more clear, there are reasons to mute and excuses to NOT to mute
• Moved wordfilter code into a service for reusability (might actually move it directly into status instead, hmm
• Properly honoring BE-sent muted property of statuses to avoid depending on relationship
• Properly handle reprööts
• send help i cannot stop saying reprööts for some reason
• Do not generate desktop notification if status in notification is muted
• Use lighter status-content instead of status for likes/favs/reacts, also fixes status content being muted in said notifications if post itself is muted

What's not fixed:

• Likes/reprööts from muted users, needs changes from BE to mark notifications as muted. pleroma#1812 (closed)