Introduce background stale AppendVec shrink mechanism (bp #9219)

[mergify]

This is an automated backport of pull request #9219 done by Mergify

Cherry-pick of b28ec43 has failed:

On branch mergify/bp/v1.0/pr-9219
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Changes to be committed:

	modified:   runtime/src/append_vec.rs

Unmerged paths:
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	added by them:   core/src/accounts_background_service.rs
	both modified:   core/src/lib.rs
	both modified:   core/src/tvu.rs
	both modified:   runtime/src/accounts_db.rs
	both modified:   runtime/src/bank/mod.rs

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[solana-grimes]

💔 Unable to automerge due to CI failure

[ryoqun]

context: this is nice-to-have (not mandatory, rather companion with #9527) perf improvement for mainnet-beta... I'm thinking to backport this depending on the required backporting woce

[ryoqun]

Closing this backport according to a resolution of not back-porting eager rent collection due to being too risky #10028.