Introduce app top bar

[AlexAndBear]

Description

Enhancement: Add app top bar component

We've added a app top bar component for consistency,
which will be used by the apps: preview, text-editor and pdf-viewer.

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

Checklist:

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

Open tasks:

• ...

[update-docs]

Thanks for opening this pull request! The maintainers of this repository would appreciate it if you would create a changelog item based on your changes.

[ownclouders]

Results for oCISFiles1 https://drone.owncloud.com/owncloud/web/26662/56/1

💥 The acceptance tests failed on retry. Please find the screenshots inside ...

webUITextEditor-textFile_feature-L13.png

webUITextEditor-textFile_feature-L21.png

webUITextEditor-textFile_feature-L29.png

webUITextEditor-textFile_feature-L37.png

webUITextEditor-textFile_feature-L44.png

webUITextEditor-textFile_feature-L50.png

webUITextEditor-textFile_feature-L56.png

webUITextEditor-textFile_feature-L70.png

webUITextEditor-textFile_feature-L71.png

webUITextEditor-textFile_feature-L80.png

webUITextEditor-textFile_feature-L81.png

webUITextEditor-textFile_feature-L82.png

webUITextEditor-textFile_feature-L83.png

webUITextEditor-textFile_feature-L84.png

💥 The acceptance tests pipeline failed. The build has been cancelled.

[pascalwengerter]

Only one minor nitpick

[pascalwengerter]

🧑‍🎨 nice!

[sonarcloud]

SonarCloud Quality Gate failed.   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

0.0% Coverage
0.0% Duplication