Notification preflet and server changes

[perelandra]

Ticket to track changes being made for phase 1 of preflet and server updates. Changes to be made:

Cleanup preflet:

• Use sliders instead of text fields for width and timeout
• Remove icon size choice (mini icon looks horrible)
• Consolidate both "Enable" checkboxes into one
• Fix Revert button, remove Apply button, add "Defaults" button
• All changes to settings saved immediately
• Live example notification message shown when settings changes are made
• Add setting for individual apps to specify their notifications should be muted
• Remove history list (to be implemented later)
• Prefelt detects if server quits or starts while preflet is running

Notification fixes: -BNotification records the signature and name of application that created it -Notification pop up view layout fixes and bold font size fix

[perelandra]

My phase 1 branch:

​https://github.com/Perelandra0x309/haiku/tree/notifications_phase1

[perelandra]

patch again master branch hrev51425