fix: unwrap edited messages during history sync parsing

[hiasinho]

Summary

• Handle edited WhatsApp messages in the history/backfill parser
• Unwrap both ProtocolMessage_MESSAGE_EDIT and top-level EditedMessage
• Preserve the original target message ID from the protocol key where available
• Add regression coverage for edited messages received through history sync

Fixes #245.

Behavior note

This fixes parsing for edited messages when they are received by wacli during future history sync, fresh initial sync, or backfill events.

It does not automatically repair existing rows already stored as:

text = NULL
display_text = "(message)"

Those rows need to be re-delivered by WhatsApp, for example through a fresh linked-device sync, before this parser fix can recover the edited body.

Testing

go test ./internal/wa ./internal/app ./internal/store ./cmd/wacli

Also tested against a fresh linked-device sync: edited messages that were previously stored as (message) were recovered with their text bodies.

[hiasinho]

One possible follow-up to make this PR stronger: add regression assertions for the two edge cases handled here too — preserving wrapper MessageContextInfo when unwrapping top-level EditedMessage, and not overwriting FromMe when the protocol key omits it. I can add those if helpful.