feat: add unmute self when in call by pressing spacebar

[aweiss-dev]

• This feature adds an event listener for SPACEBAR.
• When being in an active call and muted (while being allowed to unmute), pressing and holding the SPACEBAR will unmute the user.
• Releasing the SPACEBAR will mute the user again.

This is a working draft and needs probably more information for our users like:

• Option in the Call Settings to deactivate the feature?
• Explanation for the user or a notification that the feature exists?
• Graphical response for the user while pressing the spacebar to make it more obvious they are unmuted?

[codecov[bot]]

Codecov Report

Merging #13756 (4197901) into dev (4a77a54) will increase coverage by 2.47%. Report is 2207 commits behind head on dev. The diff coverage is 28.35%.

@@            Coverage Diff             @@
##              dev   #13756      +/-   ##
==========================================
+ Coverage   39.03%   41.50%   +2.47%     
==========================================
  Files         570      601      +31     
  Lines       21069    20812     -257     
  Branches     4550     4738     +188     
==========================================
+ Hits         8225     8639     +414     
+ Misses      11861    11067     -794     
- Partials      983     1106     +123     

[CLAassistant]

All committers have signed the CLA.