Check for prohibited words in non-secure field

[pvanderknyff]

Makes two changes:

• If the field is marked secure, and the field name is not password, fail packager validation. These connectors will not work in Tableau.
• If the field has token, password, or secret in it, and is not marked secure, fail the validation, since that suggests that field would leak customer secrets. Open to making this a non-failing warning, but given we already have a warning I'd kind of rather err on the side of caution

Also adds two new test cases to cover these scenarios.

For work item W-19338086