Make logo attributes translatable

Description

This PR makes the title and alt attribute of the custom logo translatable.

It also improves readability.

The attributes should be translated if consumed by a screen reader.

[x] Bug fix (non-breaking change which fixes an issue)
[ ] New feature (non-breaking change which adds functionality)
[ ] Breaking change (fix or feature that would cause existing functionality to change)
[x] Refactoring (a code change that neither fixes a bug nor adds a feature)
[x] Styling (changes that do not affect the meaning of the code (white-space, formatting, missing semi-colons, etc))
[ ] Development (changes that affect the build system or external dependencies)
[x] Documentation (changes that affect existing inline documentation)

[x] I pulled my branch from develop.
[x] I am submitting my pull request to develop.
[x] I have resolved any conflicts merging this pull request would create.
[x] I have checked that there aren't other open Pull Requests for the same update/change.
[x] My code follows the code style of this project.
[x] I have performed a self-review of my own code.
[x] I have commented my code, particularly in hard-to-understand areas.
[ ] (Optional) My change requires a change to the documentation.
[ ] (Optional) I have updated the documentation accordingly.
[x] (Optional) My change requires a change to the translations.
[x] (Optional) I have updated the translations accordingly.
[x] composer phpcs has passed locally.
[x] composer php-lint has passed locally.
[x] composer phpmd has passed locally.
[x] composer phpstan has passed locally.
[x] I have read the CONTRIBUTING document.