Release tracking `wallet-2.3.0`

[ValuedMammal]

This issue is for keeping track of remaining issues/PRs that can be included in the 2.3.0 release of bdk_wallet. The date of the release is still TBD.

• Add apply_block_events and apply_block_connected_to_events #336
• [RBF] Transactions with changed outputs incorrectly trigger Dropped event #344
• Potentially backport fix(wallet): Don't fail in build_fee_bump for missing parent txid  #337
• Potentially feature: Add Caravan wallet format import/export support #205