[BUGFIX] Make backend modals context-aware

[eliashaeussler]

This PR makes all backend modals context-aware which allows them to react on the currently preferred color scheme (light/dark mode).

[codeclimate[bot]]

Code Climate has analyzed commit deb1da2e and detected 0 issues on this pull request.

The test coverage on the diff in this pull request is 100.0% (50% is the threshold).

This pull request will bring the total coverage in the repository to 90.9% (0.0% change).

View more on Code Climate.

[coveralls]

Pull Request Test Coverage Report for Build 11359681374

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 90.972%

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Totals
Change from base Build 11359302810:	0.0%
Covered Lines:	1048
Relevant Lines:	1152

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💛 - Coveralls