Fix glob in stylelint task and subsequent errors

What does this MR do?

The stylelint task in the package.json currently uses the following glob (and others like this):

app/assets/stylesheets/**/*.*

On some systems (and especially when run using yarn) the ** is not expanded as expected, i.e. only files in first-level-directories are captured and files like

app/assets/stylesheets/application.scss
app/assets/stylesheets/highlight/themes/none.scss

are ignored. This MR fixes this by quoting the globs and thus preventing premature shell expansion (as it's done already for markdownlint).

In a second step, all errors occurred by this are fixed using stylelint's autofix feature (stylelint --fix) (mostly wrong quotes and missing new lines) or disabling the rules for the affected lines (mostly vendor prefixes).

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
• [-] Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• Separation of EE specific content

Availability and Testing

• [-] Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• [-] Tested in all supported browsers
• [-] Informed Infrastructure department of a default or new setting change, if applicable per definition of done