Remove jquery-contextmenu and use JSDialog dropdown

[eszkadev]

Is your feature request related to a problem?

We want to reduce old JS codebase with TypeScript. We already have own implementation of dropdowns which shares styling with all other UI components. Would be good to have 1 less dependency to maintain.

Describe the solution you'd like

• Step by step conversion (do not remove all old context menu instances in single commit)
• New code in TS
• Move "Allowed commands" list to TS file for sharing
• Create JSDialog compatible context menu
• Use it in single example case so we can test
• Later we will replace menus one by one

Code pointers:

• old context menu : https://github.com/CollaboraOnline/online/blob/main/browser/src/control/Control.ContextMenu.js
• JSDialog dropdown converted to TS: jsdialog: dropdown conversion to ts #13908 (to merge)
• see examples of JSDialog.OpenDropdown usage https://github.com/search?q=repo%3ACollaboraOnline%2Fonline+JSDialog.OpenDropdown&type=code
• see examples of menu JSON: https://github.com/CollaboraOnline/online/blob/main/browser/src/control/jsdialog/Definitions.Menu.ts#L1437