fix(vue-app): allow background customization for default loading template

[Geminii]

Types of changes

• Bug fix (a non-breaking change which fixes an issue)
• New feature (a non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Description

Relative to this MR to add the possibility to customize the background color for default loading indicator.

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly. (PR: #)
• I have added tests to cover my changes (if not applicable, please state why)
• All new and existing tests are passing.

[codecov-io]

Codecov Report

Merging #7162 into dev will not change coverage by %.
The diff coverage is n/a.

@@           Coverage Diff           @@
##              dev    #7162   +/-   ##
=======================================
  Coverage   62.82%   62.82%           
=======================================
  Files          84       84           
  Lines        3400     3400           
  Branches      928      928           
=======================================
  Hits         2136     2136           
  Misses       1017     1017           
  Partials      247      247           

Flag	Coverage Δ
#unittests	62.82% <ø> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 1a5515f...360e330. Read the comment docs.

[Geminii]

@pi0 It seems test/audit got some problem independents of this PR.
It's possible to relaunch it and check this one ?
Thanks a lot :)

[pi0]

Thanks :)