Referenda & treasury proposals SIMA governance support

[wliyongfeng]

• [x] Disable web2 user registration by chain settings. There should be a filed in chain setting file to control whether web2 user registration should be disabled.
• [x] #4264
• [x] #4265
  • When user is commenting on a discussion and this discussion is a SIMA discussion.
  • When user is commenting on any onchain proposal
• [x] #4266