Add per-user storage view

[pako81]

Description

Add per-user storage view

Related Issue

• https://github.com/owncloud/enterprise/issues/5468

Motivation and Context

Make possible to visualise used storage on per-user basis

How Has This Been Tested?

• Access ~/settings/users URL. A new column Storage Used will display the amount of used storage for every user. This option can be also opted in/out under Settings in order to align with all other available users' options.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Database schema changes (next release will require increase of minor version instead of patch)
• 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
• Changelog item

[pako81]

This is a follow-up of #40477

[phil-davis]

Note: this touches the same code areas as #40588 - we need to merge one of these, then make sure to rebase the other and test it again.

[phil-davis]

@pako81 the branch for this in your repo https://github.com/pako81/core has disappeared.

[pako81]

@phil-davis thanks for noticing it - the branch was deleted by mistake. Let's wait for #40588 to get merged and I will then open a new PR on a new branch in core repo for this one. This will not anyway be in 10.12.0 so we have some time.

[pako81]

Closing this in favour of #40657