Support classic accounts and trustlines in snapshots

[JakeUrban]

What version are you using?

22.0.0-rc.1

What did you do?

Created a snapshot like so:

stellar snapshot create --address $myaccount --address $contractid 

Then used the snapshot to create an environment for my contract test using Env::from_ledger_snapshot_file.

Because $myaccount is a Stellar account, and the function tested on $contractid results in a SAC transfer, the test failed with the following:

topics:[error, Error(Storage, MissingValue)], data:"trying to get non-existing value for contract instance"

This appears to be because trustlines are not saved to the snapshot file or are not loaded when creating the environment.

[leighmcculloch]

Requires some investigation. Snapshots are supposed to include all the trust lines of an account when an account is specified.

For example:

stellar-cli/cmd/soroban-cli/src/commands/snapshot/create.rs

Lines 284 to 286 in 90db678

	let keep = match &key {
	LedgerKey::Account(k) => current.account_ids.contains(&k.account_id),
	LedgerKey::Trustline(k) => current.account_ids.contains(&k.account_id),