refactor(selector): not hiding the first option anymore

[mfranzke]

Proposed changes

• it's inconsistent in between browsers (Safari would still display that option[hidden])
• it's inconsistent and incorrect for regular select-HTML-elements, as those would actually mark the first option as checked as well, whereas this is actually the selected one (gets transmitted in form submits etc.)
• In case that somebody would like to use floating labels or placeholder, there should be an option that the users could set to "unselect" all selectable options, or in other words "reset" any other selection. We wouldn't provide this possibility at the moment anyhow.

Resolves #4019

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Refactoring (fix on existing components or architectural decisions)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update (if none of the other choices apply)

Further comments

[github-actions]

🔭🐙🐈 Test this branch here: https://db-ux-design-system.github.io/core-web/review/4019-dbselect-dropdown-checkmark-on-first-element

[Copilot]

Copilot reviewed 1 out of 3 changed files in this pull request and generated 1 comment.

Files not reviewed (2)

• packages/components/src/components/select/select.scss: Language not supported
• packages/components/src/styles/internal/_form-components.scss: Language not supported