fix: upgrade handler and updateZoneProposal

[ajansari95]

1. Summary

Fixes #

• upgrade handler for migration of zones struct
• case for is_118 added to updateZoneProposal

2.Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

3. Implementation details

4. How to test/use

5. Checklist

• Does the Readme need to be updated?

6. Limitations (optional)

7. Future Work (optional)

[joe-bowman]

Lgtm

[codecov-commenter]

Codecov Report

Merging #459 (dabbe0a) into develop (f7603b2) will decrease coverage by 0.03%.
The diff coverage is 0.00%.

@@             Coverage Diff             @@
##           develop     #459      +/-   ##
===========================================
- Coverage    55.01%   54.98%   -0.03%     
===========================================
  Files          164      164              
  Lines        12331    12337       +6     
===========================================
  Hits          6784     6784              
- Misses        5029     5035       +6     
  Partials       518      518              

Flag	Coverage Δ
unittests	54.98% <0.00%> (-0.03%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
x/interchainstaking/keeper/proposal_handler.go	24.18% <0.00%> (-0.70%)	⬇️