Add global accessibility switch

[artonge]

Adds new global config switch to disable non-accessible features: enable_non-accessible_features.

Fix #42222 #42262

PR for the image editor: nextcloud/viewer#2100

[artonge]

/backport to stable28

[Fenn-CS]

Code looks okay, but this mean, users cannot isolate weather to use new unified search from using the grid view...

Is this okay @AndyScherzinger

[susnux]

There are two switches:

1. Enable new unified search or keep the legacy one
2. Optionally Disable all not accessible features (new unified search, grid view, image editor). As soon as one of the features is accessible we can remove it from the list of not accessible features.

[artonge]

There are two switches:

In the current state, there is only one switch, the accessibility one.

I thought the switch to toggle between unified and legacy search was only due to accessibility concern. Was I wrong?

[Fenn-CS]

I thought the switch to toggle between unified and legacy search was only due to accessibility concern. Was I wrong?

For Unified search, it could be a thing that there are accessibility issues, but the initial idea was to allow users who don't like new unified search to switch back, until we think it's stable enough.

For example issues with unified search and filtering apps, or some user running into a problem with the new search then they can disable it.

[AndyScherzinger]

Is this okay @AndyScherzinger

Yes this is okay, since we want to make things accessible anyway, where-ever possible. In case a system needs to be accessible by law, than like it is designed it is a yes/no question, hence a single config switch.

[AndyScherzinger]

For Unified search, it could be a thing that there are accessibility issues, but the initial idea was to allow users who don't like new unified search to switch back, until we think it's stable enough.

That switch is also still there. So all good.

[backportbot-nextcloud]

The backport to stable28 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable28
git pull origin stable28

# Create the new backport branch
git checkout -b fix/foo-stable28

# Cherry pick the change from the commit sha1 of the change against the default branch
# This might cause conflicts. Resolve them.
git cherry-pick abc123

# Push the cherry pick commit to the remote repository and open a pull request
git push origin fix/foo-stable28

Error: Unknown error

More info at https://docs.nextcloud.com/server/latest/developer_manual/getting_started/development_process.html#manual-backport