Add birthdays to MASP keys

[batconjurer]

Describe your changes

Partially addresses Issue #2900. Viewing and spending keys can no be given birthdays in the form of block heights which are loaded into shielded sync. Shielded sync will not try to decrypt a block before a keys birthday with said key.

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 71.25984% with 73 lines in your changes missing coverage. Please review.

Project coverage is 61.31%. Comparing base (f08d3f2) to head (00df744).
Report is 64 commits behind head on main.

Files	Patch %	Lines
crates/sdk/src/wallet/mod.rs	0.00%	32 Missing ⚠️
crates/sdk/src/wallet/store.rs	0.00%	18 Missing ⚠️
crates/sdk/src/wallet/keys.rs	71.15%	15 Missing ⚠️
crates/node/src/bench_utils.rs	0.00%	4 Missing ⚠️
crates/core/src/masp.rs	0.00%	3 Missing ⚠️
crates/sdk/src/masp.rs	99.31%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3653      +/-   ##
==========================================
+ Coverage   61.28%   61.31%   +0.03%     
==========================================
  Files         312      312              
  Lines      101337   101548     +211     
==========================================
+ Hits        62103    62267     +164     
- Misses      39234    39281      +47     

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[sug0]

These changes look good against main. When we integrate them with the phase 3 shielded sync code, we should optimize this function accordingly:

https://github.com/anoma/namada/blob/b6895337d90649abbd509f3416210d60bc9dbae4/crates/sdk/src/masp/shielded_sync/dispatcher.rs#L774-L791

Right now, it's always attemtpting to scan txs without checking the heights of viewing keys.

[sug0]

ah benches are broken