Redesign small fixes

[kulmann]

Description

This PR fixes some small issues from the first redesign iteration:

• topbar stays visible on pages that don't require authentication, but with a reduced set of items
• margins around and in between browser top edge <-> topbar <-> app container <-> browser bottom edge are now all equal
• white border artifact on the left of the sidebar nav is fixed
• scrollbar issues are fixed
• height issue in app provider is fixed
• bonus: fixes a console warning about type check failures when passing undefined into OcResourceSize inside ResourceTable

Related Issue

• Works towards Redesign Follow-up #6203

Motivation and Context

Finetune the main layout

How Has This Been Tested?

• manually in chrome and firefox

Screenshot

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

Checklist:

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

[kulmann]

cc @wkloucek as this fixes #6203 (comment)

[ownclouders]

Results for oC10Files1 https://drone.owncloud.com/owncloud/web/21601/16/1
The following scenarios passed on retry:

• webUIMarkdownEditor/markdownFile.feature:29

[ownclouders]

Results for oC10Files2 https://drone.owncloud.com/owncloud/web/21601/17/1
💥 The acceptance tests pipeline failed. The build has been cancelled.

[ownclouders]

Results for oCISFiles2 https://drone.owncloud.com/owncloud/web/21602/56/1
💥 The acceptance tests pipeline failed. The build has been cancelled.

[ownclouders]

Results for oC10Files2 https://drone.owncloud.com/owncloud/web/21602/17/1
💥 The acceptance tests pipeline failed. The build has been cancelled.

[ownclouders]

Results for oC10SharingExternalRoot https://drone.owncloud.com/owncloud/web/21610/41/1
💥 The acceptance tests pipeline failed. The build has been cancelled.

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

100.0% Coverage
0.0% Duplication

[lookacat]

LGTM 💪 will merge for now and take over the PR