Usability improvements for CM/Track V3

The following usability improvements for the CM/Track V3 have been made.

Accessibility of login/logout page improved (#666719)

The accessibility of the login and logout pages has been improved by adding missing lang attributes and alt tags and increasing the contrast for success messages.

Alternative text for images (#666964)

The rich text editor has been adjusted by adding the button Alternative Text which allows to add a textual description for images inserted in rich text fields and comments. Additionally, any existing ALT attributes will be displayed in the case history. This aligns CM/Track V3 with the accessibility features already available in the Web Client.