Fixes #3260: Buttonless habits full width

When the user has neither a plus nor a minus button on
one of their habits, the habit’s title will now span the entire
width of the task div instead of having a gap to the left.
Flag icon opens blank modal
Added heading and body of flag modal
Renamed everything from flag to abuseFlag
Added text-danger span on username
Corrected tooltip name
Added buttons to footer, cleaned up functions
Added a flags key to message object
Renamed flagChat to flagChatMessage
Removed flag from system notifications
Added some logic for adding flags
Error handling for if message already flagged
Give flag text danger class and already reported message if already
reproted
Prevent modal from popping up if already reported
Converted heading to paragraph
Added text of message to make sure user clicked the right flag
Added todo for paglias
Added note for paglias
feat(flag-message): add server methods
Merge branch 'develop' of github.com:HabitRPG/habitrpg into add-flag-to-chat