Fixed new unthemed elements in 5.2.0 workspace

[chotaire]

Fixed unthemed elements in administrative workspace, introduced in 5.2.0.

This affected the following pages:

• Administration -> Workspace -> Users
• Administration -> Workspace -> Rooms
• Administration -> Workspace -> Invites
• Administration -> Workspace -> View Logs
• Administration -> Workspace -> Custom Sounds
• Administration -> Workspace -> Email Inboxes
• Administration -> Workspace -> Custom Emoji
• Administration -> Workspace -> Integrations
• Administration -> Workspace -> Oauth Applications
• Administration -> Workspace -> Custom User Status
• Administration -> Workspace -> Permissions
• Administration -> Workspace -> Settings (element surround search bar when scrolling down)
• My Account -> Personal Access Tokens

This fixes #200. It is recommended to merge #196 and #198 for additional fixes throughout administrative workspace.

[paulchen]

I just tried out the changes from this pull request. Looks good.