wpcomsh: Fix generate POT scanned file paths

[yuliyan]

Fixes p1719903725313999-slack-C02AED43D

Proposed changes:

• Update the find command in generate-pot.sh to follow symlinks so that it scans the files in vendor/ that are symlinked to the packages in the monorepo.
• Set sudirectory max depth to 10 and ignore nested vendor and wordpress directories to prevent unwanted files from scanning.
• Update language files.

Other information:

• [ ] Have you written new tests for your changes, if applicable?
• [ ] Have you checked the E2E test CI results, and verified that your changes do not break them?
• [ ] Have you tested your changes on WordPress.com, if applicable (if so, you'll see a generated comment below with a script to run)?

Jetpack product discussion

Does this pull request change what data or activity we track or use?

Testing instructions:

• Code review projects/plugins/wpcomsh/bin/i18n/generate-pot.sh.
• Inspect projects/plugins/wpcomsh/languages/wpcomsh.pot and confirm the newly added strings are all expected to be there.
• Run make i18n in projects/plugins/wpcomsh to confirm it runs as expected.