[web] Add action: "Duplicate" file / folder

[tbsbdr]

Description

User Stories

• As a user who is not familiar with keyboard shortcuts I want an obvious way to duplicate files/folders so that I can have a copy of a resource.

Value

• improve usability
• enhance productivity

Acceptance Criteria

• Add new Context Menu Option "Duplicate" (folders-line)
• Option is available for folders and files (each: single or multiple)
• position: below "Rename"
• after clicking on "duplicate", the selected resource(s) get duplicated with the appended (1) (like klicking on "keep both" in the file conflict resolution dialog)

Please track times

Definition of ready

[ ] everybody needs to understand the value written in the user story
[ ] acceptance criteria has to be defined
[ ] all dependencies of the user story need to be identified
[ ] feature should be seen from an end user perspective
[ ] user story has to be estimated
[ ] story points need to be less then 20

Definition of done

• Functional requirements
  [ ] functionality described in the user story works
  [ ] acceptance criteria are fulfilled
• Quality
  [ ] code review happened
  [ ] CI is green
  [ ] critical code received unit tests by the developer
  [ ] automated tests passed (if automated tests are not available, this test needs to be created and passed
• Non-functional requirements
  [ ] no sonar cloud issues

Visuals

cc @elizavetaRa

[JammingBen]

Also see #9632

[tbsbdr]

split into #10016

[michaelstingl]

Align file action icons with mobile apps?

Duplicate already available in iOS app ✅	Could be added to Android too…

[kulmann]

@michaelstingl icon is not available in remixicon icon-set. :-( closest match would be file-copy-2, see https://remixicon.com - but that's not such a good fit either.