[ABO-169|ABO-215] Additional rules for staking attributes

[DidacSF]

Description

This PR adds additional rules for Contract clauses as requested here -> https://ajunanetwork.atlassian.net/browse/ABO-169

It also expands the possible value comparisons as requested here -> https://ajunanetwork.atlassian.net/browse/ABO-215

Type of changes

• build: Changes that affect the build system or external dependencies (eg, Cargo, Docker)
• ci: Changes to CI configuration
• docs: Changes to documentation only
• feat: Changes to add a new feature
• fix: Changes to fix a bug
• refactor: Changes that do not alter functionality
• style: Changes to format the code
• test: Changes to add missing tests or correct existing tests

Checklist

• Tests for the changes have been added
• Necessary documentation is added (if appropriate)
• Formatted with cargo fmt --all
• Linted with cargo clippy --all-features --all-targets
• Tested with cargo test --workspace --all-features --all-targets

[codecov]

Codecov Report

Attention: 32 lines in your changes are missing coverage. Please review.

Comparison is base (7f0f9c0) 75.56% compared to head (695aac6) 74.95%.

Files	Patch %	Lines
pallets/ajuna-nft-staking/src/contracts.rs	23.80%	32 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop     #353      +/-   ##
===========================================
- Coverage    75.56%   74.95%   -0.62%     
===========================================
  Files           33       33              
  Lines         3520     3561      +41     
===========================================
+ Hits          2660     2669       +9     
- Misses         860      892      +32     

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