Revert "Fix visitor attachment send crashes" (#1511)

[DavDo]

Jira issue:
https://glia.atlassian.net/browse/MOB-xxx

What was solved?

Reverts PR #1511 ("Fix visitor attachment send crashes") on development. The two commits introduced by that PR are reverted here:

• Revert "Guard chat item lookup when marking attachment send state" (ee9ec47f)
• Revert "Give LocalAttachment a stable unique id" (b4c23afb)

Additional info:

• Is the feature sufficiently tested? All tests fixed? Necessary unit, acceptance, snapshots added? Check that at least new public classes & methods are covered with unit tests
• Did you add logging beneficial for troubleshooting of customer issues?
• Did you add new logging? We would like the logging between platforms to be similar. Refer to Logging from Android SDKs → Things to consider for newly added logs in Confluence for more information.

Screenshots:

[snyk-io]

✅ Snyk checks have passed. No issues have been found so far.

Status	Scan Engine	Critical	High	Medium	Low	Total (0)
✅	Open Source Security	0	0	0	0	0 issues
✅	Licenses	0	0	0	0	0 issues

💻 Catch issues earlier using the plugins for VS Code, JetBrains IDEs, Visual Studio, and Eclipse.