tx & VP ctx and tests refactors

[tzemanovic]

Describe your changes

Depends-On: #3807

• moved Ctx from tx_prelude into tx_env to declare & implement trait TxEnv in one crate so that it can be tested without additional deps

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

[codecov]

Codecov Report

Attention: Patch coverage is 86.08247% with 54 lines in your changes missing coverage. Please review.

Project coverage is 72.75%. Comparing base (1008f60) to head (e73c499).
Report is 49 commits behind head on main.

Files with missing lines	Patch %	Lines
crates/tx_env/src/ctx.rs	82.88%	45 Missing ⚠️
crates/tx_prelude/src/proof_of_stake.rs	75.00%	3 Missing ⚠️
wasm/vp_implicit/src/lib.rs	90.90%	2 Missing ⚠️
crates/tx_prelude/src/ibc.rs	90.00%	1 Missing ⚠️
wasm/tx_change_consensus_key/src/lib.rs	0.00%	1 Missing ⚠️
wasm/tx_change_validator_metadata/src/lib.rs	0.00%	1 Missing ⚠️
wasm/tx_claim_rewards/src/lib.rs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3787      +/-   ##
==========================================
+ Coverage   72.68%   72.75%   +0.06%     
==========================================
  Files         338      340       +2     
  Lines      104340   104723     +383     
==========================================
+ Hits        75837    76187     +350     
- Misses      28503    28536      +33     

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[mergify]

Merge Protections

Your pull request matches the following merge protections and will not be merged until they are valid.

⛓️ Depends-On Requirements

Requirement based on the presence of Depends-On in the body of the pull request

• depends-on = anoma/namada#3807 [⛓️ env agnostic VPs #3807]