feat: [OCISDEV-531] add vault capabilities to the OCS capabilities endpoint

[2403905]

Description

Added vault capabilities to the OCS capabilities endpoint

Added OCIS_ENABLE_VAULT_MODE / FRONTEND_ENABLE_VAULT_MODE config option to
the frontend service. When enabled, the OCS capabilities endpoint advertises
vault.enabled = true. Clients can request vault-specific capabilities via
/ocs/v2.php/cloud/capabilities?vault=true, which returns a response with
public sharing and federation sharing disabled.
The part of the Story feat/OCISDEV-533-graph

Related issue owncloud/reva#584

Related Issue

• Fixes <issue_link>

Motivation and Context

How Has This Been Tested?

• test environment:
• test case 1:
• test case 2:
• ...

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Technical debt
• Tests only (no source changes)

Checklist:

• Code changes
• Unit tests added
• Acceptance tests added
• Documentation ticket raised:

[jvillafanez]

I think we'll have to figure out how we can implement the capabilities properly.

Right now, with this PR, we have 3 different flags that must be enabled for the feature to work properly. The flags also belong to different services, so it might be difficult to find them unless all the related flags are documented together. As such, it's possible for the capability flag to be enabled while the rest of the flags are disabled, so you'd advertise a feature that is disabled.
In addition, it's questionable to have a flag just for advertisement. The flag doesn't affect the feature in any meaningful way.

I'm not sure if we have better options at the moment, but I think it's worthy to add it in the TODO list.

[jvillafanez]

OCIS_ENABLE_VAULT_MODE should be used instead since it's the preferred option

[2403905]

updated

[jvillafanez]

quick change

[2403905]

I think we'll have to figure out how we can implement the capabilities properly.

Right now, with this PR, we have 3 different flags that must be enabled for the feature to work properly. The flags also belong to different services, so it might be difficult to find them unless all the related flags are documented together. As such, it's possible for the capability flag to be enabled while the rest of the flags are disabled, so you'd advertise a feature that is disabled. In addition, it's questionable to have a flag just for advertisement. The flag doesn't affect the feature in any meaningful way.

I'm not sure if we have better options at the moment, but I think it's worthy to add it in the TODO list.

@jvillafanez All of 3 flags have a common one OCIS_ENABLE_VAULT_MODE. The readme will be provided in a feature branch feat/OCISDEV-533-graph