Do not mess with @nextcloud/vue styles and fix navigation header a11y

[susnux]

• Resolves [BITV]: Not possible to close left sidebar on small screens #2278
• Replacement for chore(NcAppNavigationToggle): add comments nextcloud-libraries/nextcloud-vue#5148 (review)

The real problem for that issue is that photos messes with the app navigation button.
Also fixing the overall accessibility of the header bar on small devices, currently it overflows the screen.
Including the new album button to have different aria-label compared to button text, for small mobile devices we need a icon only button to not overflow.

Screenshots

before	after

[JuliaKirschenheuter]

/backport to stable28

[github-actions]

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