Workflow - approval - groups

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Is your feature request related to a problem? Please describe.
The workflow - and especially the approval feature - is very nice and very much needed. However it would REALLY benefit from adding the possibility of requesting Nextcloud group memberships as well.
Access to/permissions to both shares, specific files, tags, apps and decentralised administration, is supporting using groups. This essentially allows for an easy "role" based access control design, but unless you are a bigger organization with an internal servicedesk, or if you have an IAM solution, there is no really good way of decentralising group memberships based on policies. This makes it a constant manual process where requests to get access to apps and protected shares, is happening using talk.

Describe the solution you'd like
Based on simple, protected md or txt files with tags, the approval workflow can be used as-is to spawn an approval request with no further need for customization besides scope of possible tags. Then add a form: Request access. In form: pick from an admin defined list of groups, where groups you already has, is stripped. Add a mandatory comment, and on submit, it will create a txt or md file in a special location with GUID as filename and content is just <userID>=<group>. Which tag it is added with, is dependant on which tags is added to the actual group. This ensures that default workflow and approval configs can be used to determine the correct approver. Then Allow Nextcloud to be able to pick up that file with a specific tag or from a specific location, open it, read the content - which is a username and a group name - assign the user to that group if tagged with the approved tag. Add administration menu to remove approval again, hence group will be removed, and the txt file be archived.
This feature will require the LDAP write APP if using LDAP backend, or allow group memberships to be hybrid: Both maintained in NC DB and in external LDAP.

Describe alternatives you've considered
Use an external IAM platform to manage group memberships in LDAP. However this solution is beyond Nextcloud and fits poorly with most none-enterprise users. And it will move the governance and user experience out of NC.
It COULD be possible to use the external sites app, allow a 3rd party selfservice portal as an iframe, utilizing federation, to achieve something that FEELS native. Again this is not for the majority of users.

Additional context
Add any other context or screenshots about the feature request here.

Start by reviewing the existing Workflow approval feature and the LDAP write app integration; the issue does not identify specific files, tests, or entry points. Done would mean a group-access request form, approval-driven membership changes, support for LDAP or hybrid memberships, and an administration path to remove approval and archive the request.