refactor: MsgUpdateZRC20 into MsgPauseZrc20 and MsgUnPauseZRC20

[kingpinXD]

Description

Refactor MsgUpdateZRC20 into MsgPauseZrc20 and MsgUnPauseZRC20

MsgPauseZRC20 : PolicyType_groupEmergency MsgUnPauseZRC20 PolicyType_groupOperational

Closes: https://github.com/zeta-chain/node/issues/2244

Type of change

• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] This change requires a documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Include instructions and any relevant details so others can reproduce.

• [ ] Tested CCTX in localnet
• [ ] Tested in development environment
• [ ] Go unit tests
• [ ] Go integration tests
• [ ] Tested via GitHub Actions

Checklist:

• [ ] I have added unit tests that prove my fix feature works

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 86.36364% with 12 lines in your changes are missing coverage. Please review.

Project coverage is 68.86%. Comparing base (8144a09) to head (1945878).

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #2262      +/-   ##
===========================================
+ Coverage    68.82%   68.86%   +0.04%     
===========================================
  Files          261      263       +2     
  Lines        16261    16302      +41     
===========================================
+ Hits         11191    11226      +35     
- Misses        4589     4594       +5     
- Partials       481      482       +1     

Files	Coverage Δ
x/fungible/types/message_pause_zrc20.go	100.00% <100.00%> (ø)
x/fungible/types/message_unpause_zrc20.go	100.00% <100.00%> (ø)
x/fungible/keeper/msg_server_pause_zrc20.go	77.77% <77.77%> (ø)
x/fungible/keeper/msg_server_unpause_zrc20.go	77.77% <77.77%> (ø)