fix(rollapp): validate rollapp token metadata

[VictorTrustyDev]

Description

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RollApp denom metadata will be used to put into x/bank denom metadata thus it should valid token-metadata-convension of x/bank.

Currently implementation does not validate it correctly. This PR aims to fix it.

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All items are required. Please add a note to the item if the item is not applicable and
please add links to any relevant follow-up issues.

PR review checkboxes:

I have...

• Added a relevant changelog entry to the Unreleased section in CHANGELOG.md
• Targeted PR against the correct branch
• included the correct type prefix in the PR title
• Linked to the GitHub issue with discussion and accepted design
• Targets only one GitHub issue
• Wrote unit and integration tests
• Wrote relevant migration scripts if necessary
• All CI checks have passed
• Added relevant godoc comments

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For Reviewer:

• Confirmed the correct type prefix in the PR title
• Reviewers assigned
• Confirmed all author checklist items have been addressed

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After reviewer approval:

• In case the PR targets the main branch, PR should not be squash merge in order to keep meaningful git history.
• In case the PR targets a release branch, PR must be rebased.

[omritoptix]

@VictorTrustyDev linter issues

[VictorTrustyDev]

@omritoptix help me, I don't use lint :)

Btw don't forget the RollApp side

[codecov]

Codecov Report

Attention: 3 lines in your changes are missing coverage. Please review.

Comparison is base (248650a) 30.70% compared to head (7e761cb) 30.78%.

Files	Patch %	Lines
x/rollapp/types/token_metadata.go	88.46%	2 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #471      +/-   ##
==========================================
+ Coverage   30.70%   30.78%   +0.07%     
==========================================
  Files         200      201       +1     
  Lines       28460    28491      +31     
==========================================
+ Hits         8738     8770      +32     
+ Misses      18324    18322       -2     
- Partials     1398     1399       +1     

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redundant validation

[VictorTrustyDev]

@omritoptix
Done:

• Rebase
• Update code follow comment