dev/core#2989 - validate campaign id for contribution import

[kurund]

Overview

Fixes: https://lab.civicrm.org/dev/core/-/issues/2989

[civibot]

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[demeritcowboy]

• General standards
  • [r-explain] PASS
  • [r-user] PASS
  • [r-doc] PASS
  • [r-run] PASS
    • The error string should have ts() but I see none of them do in this section so ok for now.
• Developer standards
  • [r-tech] PASS
  • [r-code] PASS
  • [r-maint] ?
    • It would be nice to have a test.
  • [r-test] Pending
    • Hasn't run in a while. Jenkins re-test this please.

[kurund]

@demeritcowboy

Thank you :)