[ABO-213] Delegate reward to a different account

[DidacSF]

Description

This PR adds the reward delegation to the claim extrinsic as detailed here https://ajunanetwork.atlassian.net/browse/ABO-213

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

All modified and coverable lines are covered by tests ✅

Comparison is base (fce431d) 75.57% compared to head (8e9e0d1) 75.60%.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop     #380      +/-   ##
===========================================
+ Coverage    75.57%   75.60%   +0.02%     
===========================================
  Files           33       33              
  Lines         3517     3517              
===========================================
+ Hits          2658     2659       +1     
+ Misses         859      858       -1     

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