feat: replace toustui editor with md editor

[LukasHirt]

Description

The original lib used in the text editor component is having CVE but is no longer maintained. Since we do not wish to maintain a fork of the lib, we decided to replace it. This brings in https://github.com/imzbf/md-editor-v3

Related Issue

• refs https://github.com/owncloud/enterprise/issues/7077

Motivation and Context

No CVE === secure oCIS

How Has This Been Tested?

• test environment: chrome & firefox
• test case 1: open text editor to edit .txt file
• test case 2: open text editor to edit .md file
• test case 3: open space and see & edit description
• test case 4: open app in app store and see description

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
• Documentation
• Maintenance (e.g. dependency updates or tooling)

Open tasks:

• fix errors with codemirror when running dev server
• add changelog
• fix tests

[CLAassistant]

All committers have signed the CLA.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud