Resolve Rust 1.88 clippy string lints and format strings (svm + misc)

[steviez]

Problem

Working towards #6850, broken out from #6854

Summary of Changes

1. Set the Rust version to 1.88.0 (only temporarily, reverted after)
   

   agave/rust-toolchain.toml

   Line 2 in 96bef97

   channel = "1.87.0"

2. Run cargo clippy --fix --tests
3. Some manual cleanup on modified files

[mergify]

The Firedancer team maintains a line-for-line reimplementation of the
native programs, and until native programs are moved to BPF, those
implementations must exactly match their Agave counterparts.
If this PR represents a change to a native program implementation (not
tests), please include a reviewer from the Firedancer team. And please
keep refactors to a minimum.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 33.33333% with 16 lines in your changes missing coverage. Please review.

Please upload report for BASE (master@1e119f0). Learn more about missing BASE report.

Additional details and impacted files

@@            Coverage Diff            @@
##             master    #6910   +/-   ##
=========================================
  Coverage          ?    83.2%           
=========================================
  Files             ?      853           
  Lines             ?   375928           
  Branches          ?        0           
=========================================
  Hits              ?   312953           
  Misses            ?    62975           
  Partials          ?        0           

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[steviez]

Resolved the items Lucas called out + force pushed to rebase on top of #6961

[steviez]

Had to force push to rebase on top of #6947