Split out ibc-clients crate

[seanchen1991]

Part of: #965

Description

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PR author checklist:

• Added changelog entry, using unclog.
• Added tests.
• Linked to GitHub issue.
• Updated code comments and documentation (e.g., docs/).
• Tagged one reviewer who will be the one responsible for shepherding this PR.

Reviewer checklist:

• Reviewed Files changed in the GitHub PR explorer.
• Manually tested (in case integration/unit/mock tests are absent).

[seanchen1991]

@Farhad-Shabani Two things before this PR is fully ready for review and merging:

1. The ibc_core::extra::tendermint::validate_self_client module complains about not being to find the latest_height method on the ClientState type (imported from ibc_client_tendermint_types::client_state::ClientState). This is because the latest_height method is implemented for ClientState as part of the ClientStateCommon trait: this trait implementation exists in the handlers part of the ics07-tendermint crate, not the ics07-tendermint/types sub-crate. How should we go about resolving this? Should the ClientStateCommon trait implementation be moved to the types sub-crate? We could also opt to move the latest_height function out of the ClientStateCommon trait and have it exist standalone in the types sub-crate. What's the preferred way to address this?
2. The ibc-testkit crate's import paths still need to be updated.

[Farhad-Shabani]

Two things before this PR is fully ready for review and merging

Big thanks @seanchen1991 for taking care of the clients migration! 🙌
I made a few more tweaks to the ibc-core PR. Some code shuffled around, and I ditched ibc-core-extra crate, moving its codebase to the other right crates. I've updated your PR as well to sync up with these changes and also tackled issues you pointed out earlier.

[codecov]

Codecov Report

Attention: 197 lines in your changes are missing coverage. Please review.

Comparison is base (60fd38d) 69.88% compared to head (c84fad8) 70.25%.

Files	Patch %	Lines
...s/ibc-clients/ics07-tendermint/src/client_state.rs	59.53%	155 Missing ⚠️
.../ics24-host/tendermint/src/validate_self_client.rs	0.00%	19 Missing ⚠️
...ents/ics07-tendermint/types/src/consensus_state.rs	47.05%	9 Missing ⚠️
...bc-testkit/src/utils/dummies/clients/tendermint.rs	53.33%	7 Missing ⚠️
...ics07-tendermint/src/client_state/update_client.rs	77.77%	4 Missing ⚠️
.../ics07-tendermint/src/client_state/misbehaviour.rs	75.00%	2 Missing ⚠️
crates/ibc-testkit/src/testapp/ibc/clients/mod.rs	50.00%	1 Missing ⚠️

Additional details and impacted files

@@                     Coverage Diff                     @@
##           farhad/migrate-ibc-core     #971      +/-   ##
===========================================================
+ Coverage                    69.88%   70.25%   +0.37%     
===========================================================
  Files                          175      175              
  Lines                        17362    17698     +336     
===========================================================
+ Hits                         12133    12434     +301     
- Misses                        5229     5264      +35     

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[Farhad-Shabani]

fyi: to avoid confusion arising from the varied use of ClientState in different types and implementations, I've updated the naming around. The newly defined newtype ClientState is now named ClientStateWrapper, while the original Tendermint ClientState struct has been preserved as TmClientState wherever it is imported. The term ClientState still refers to the trait, ensuring consistency in naming with the ConsensusState as well. Hope it works.

[Farhad-Shabani]

Merged this PR to have a smoother review of changes within a consolidated branch.