Command confirmation client-side dialog

Extends CommandAttribute to support prompting for confirmation on the
client before sending the message.
LockCommand Confirmed

LockCommand confirms with client-side dialog before locking a room.
Migrate SendMessage UI Logic

Moves message display logic into chat.ui.js. Commands are stored in
array and lookup format.
Updated livestamp.js
Manually applied PR from SignalR
- Applied https://github.com/SignalR/SignalR/pull/2772
Patched issue with SignalR js
Removed livestamp map file.
Audio and Toast notifications for Nudge event
Toast notification appends roomName if present.
Added '<3' as alias for :heart:
Changed Regex to allow pulls to show as well as issues

This will allow pull requests to be shown like issues.
Merge pull request #1060 from khellang/patch-1

Changed Regex to allow pulls to show as well as issues
Merge pull request #1059 from khellang/patch-3

Added '<3' as alias for :heart:
Fix #1064 - Make lobby room list have pointer cursor
Merge pull request #1069 from JabbR/lobby-cursor

Fix #1064 - Make lobby room list have pointer cursor
Merge branch 'nudge-notifications' of https://github.com/nerdfury/JabbR into nerdfury-nudge-notifications
Merge branch 'client-side-dialogs' of https://github.com/garysharp/JabbR-Fork into garysharp-client-side-dialogs
Updated SignalR version
Configurable Content Providers

- Added configurable content providers
- Removed 8 built-in content providers
- Added 8 default content providers to config
Content Providers can be disabled through admin

Makes the built-in content providers togglable from the admin
ui. Now you can turn on/off providers as well as add additional
providers dynamically.