Added new ChangeOp for claim operations

Change-Id: I4506c94c706769c368b6351a07007d2e893afcc5
Use ChangeOps for wbsetclaimvalue and wbcreateclaim

- wbsetclaimvalue & wbcreateclaim are now using ChangeOpClaim
- autocomment functionality added to wbsetclaimvalue
- these modules now also allow custom edit summaries

Bug: 41490
Bug: 50307
Change-Id: I0521a20bf6f600a952831418ebd4ef02bcb3f52f
Move claimGuidValidator into ClaimModificationHelper

Change-Id: I76c1c9a0ccbe69b22daf95ee0cb10b648df17d65
Refactoring of wbremoveclaims API module

- it is now only allowed to remove claims from the same entity
- uses ChangeOpClaim now
- custom edit summaries and improved autocomment

Change-Id: Ie1f38f0803768bcf97dc6e698355a9ddba1c0359
Move initialization of ClaimModificationHelper to ModifyClaim

Change-Id: I4d3383071562a81cb90eb67203433bc3e34d7f11
Adding tests for ClaimModificationHelper

Change-Id: Ib45502834f0603a755cbc1d5e2151fd2c7ba72ff
Improve some API tests

Change-Id: I6fb3995ed610f56fc87846e7e8ceffd409de7ac3
Merge changes I6fb3995e,Ib4550283,I4d338307,Ie1f38f08,I76c1c9a0,I0521a20b,I4506c94c

* changes:
  Improve some API tests
  Adding tests for ClaimModificationHelper
  Move initialization of ClaimModificationHelper to ModifyClaim
  Refactoring of wbremoveclaims API module
  Move claimGuidValidator into ClaimModificationHelper
  Use ChangeOps for wbsetclaimvalue and wbcreateclaim
  Added new ChangeOp for claim operations