Upgrade VoteState

[carllin]

Problem

No way to upgrade to new VoteState without breaking ABI

Depends on and includes changes from #8303

Summary of Changes

Convert VoteState's between different releases using an enum to differentiate the types

TODO: convert snapshots to include new VoteStates

Fixes #

[carllin]

@mvines, I dislike this state() function because it requires whoever modifies this code to know that vote accounts are special/need special handling, and can't directly be deserialized into a VoteState object like its other counterparts(stake, storage, nonce, etc.). Ideally the Account type carries the type of the object it's storing so we can avoid this footgun (even in this PR, hopefully I haven't missed any conversions directly to VoteState from account.data), but that's a more sweeping change I can add as a follow-up.

[t-nelson]

solana/sdk/src/account_utils.rs

Lines 38 to 40 in b18e405

	fn state(&self) -> Result<T, InstructionError> {
	self.try_account_ref()?.state()
	}

We could add a trait that requires an implementation of fn convert_to_current() then make it a bound on T for State<T> and StateMut<T> hide it in the fn state() implementations

[codecov]

Codecov Report

Merging #8348 into master will decrease coverage by <.1%.
The diff coverage is 90.3%.

@@           Coverage Diff            @@
##           master   #8348     +/-   ##
========================================
- Coverage    80.3%   80.3%   -0.1%     
========================================
  Files         254     256      +2     
  Lines       56235   56341    +106     
========================================
+ Hits        45173   45254     +81     
- Misses      11062   11087     +25