PoS: update ClaimRewards action to add receiver

[tzemanovic]

Describe your changes

Follow-up to #4427 (and based on it - diff 0ac1938)

Changes the ClaimRewards action to the new type with added receiver field

Checklist before merging

• If this PR has some consensus breaking changes, I added the corresponding breaking:: labels
  • This will require 2 reviewers to approve the changes
• If this PR requires changes to the docs or specs, a corresponding PR is opened in the namada-docs repo
  • Relevant PR if applies:
• If this PR affects services such as namada-indexer or namada-masp-indexer, a corresponding PR is opened in that repo
  • Relevant PR if applies:

[codecov]

Codecov Report

Attention: Patch coverage is 56.71642% with 29 lines in your changes missing coverage. Please review.

Project coverage is 74.46%. Comparing base (c29fd32) to head (0ac1938).
Report is 33 commits behind head on main.

Files with missing lines	Patch %	Lines
crates/sdk/src/tx.rs	36.36%	14 Missing ⚠️
wasm/tx_claim_rewards/src/lib.rs	0.00%	6 Missing ⚠️
crates/tx_prelude/src/proof_of_stake.rs	0.00%	3 Missing ⚠️
wasm/vp_implicit/src/lib.rs	0.00%	2 Missing ⚠️
wasm/vp_user/src/lib.rs	0.00%	2 Missing ⚠️
crates/proof_of_stake/src/lib.rs	92.30%	1 Missing ⚠️
crates/sdk/src/lib.rs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4429      +/-   ##
==========================================
- Coverage   74.54%   74.46%   -0.08%     
==========================================
  Files         339      339              
  Lines      110504   110660     +156     
==========================================
+ Hits        82374    82403      +29     
- Misses      28130    28257     +127     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.