Modular 02-client

[AdityaSripal]

Description

• Adds interface methods to ClientState and MsgCreateClient to keep 02-client modular
• Leaves local-host client as a "special case" with its own handling. This makes sense because local-host handling is so different from everything else. Better to leave it as a special case and make all "foreign" clients conform to a cleaner interface

TODO:

• fix 07-tendermint/types tests

closes: #6064

---

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• Targeted PR against correct branch (see CONTRIBUTING.md)
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
• Code follows the module structure standards.
• Wrote unit and integration tests
• Updated relevant documentation (docs/) or specification (x/<module>/spec/)
• Added relevant godoc comments.
• Added a relevant changelog entry to the Unreleased section in CHANGELOG.md
• Re-reviewed Files changed in the Github PR explorer

[codecov]

Codecov Report

Merging #6515 into master will decrease coverage by 1.08%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #6515      +/-   ##
==========================================
- Coverage   56.36%   55.27%   -1.09%     
==========================================
  Files         470      383      -87     
  Lines       28234    22793    -5441     
==========================================
- Hits        15913    12598    -3315     
+ Misses      11195     9235    -1960     
+ Partials     1126      960     -166     

[colin-axner]

see comment specifically:

moving consensus state outside of client state results in:
change the CheckHeaderAndUpdateState to receive in the client store so the correct consensus state can be retrieved. This maybe have ramifications with trying to make 02-client modular, see issue#6064

it may be useful for clients to have access to their consensus state in order to update

[AdityaSripal]

We still wouldn't need to pass in clientstore, just make caller query for latest consensus state and pass it in. Though I'm in favor of keeping lates consensus-state in client state

[colin-axner]

We should remove GetClientType interface func with this pr, I don't see any reason for it's use? Should just use the underlying struct type if needed

[AdityaSripal]

Closing in favor of #7028