Secure writes to the storage

[exalate-issue-sync]

Description

Introduce an If-Match Header on the etag

cs3org/reva#4

User Stories

• If editing a file I want to be sure not to overwrite some others changes in the same file

Value

Acceptance Criteria

• Writes via WebDAV can now use the If-Match header and the decompose file systems supports it on a single node
• initiateupload needs to be aware of the if-Match value

Definition of done

• Functional requirements
  [ ] functionality described in the user story works
  [ ] acceptance criteria are fulfilled
• Quality
  [ ] codre 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

[exalate-issue-sync]

David Christofas commented: Here is the PR for this ticket: cs3org/reva#2547