ACL: move isPluginActive from CREATOR to VIEWER; fixes #7535

[SlavikCA]

Change Summary

This change will enable VIEWER to receive emails, whenever new entry added via FORM
fixes #7535

Change type

• feat: (new feature for the user, not a new feature for build script)
• fix: (bug fix for the user, not a fix to a build script)
• docs: (changes to the documentation)
• style: (formatting, missing semi colons, etc; no production code change)
• refactor: (refactoring production code, eg. renaming a variable)
• test: (adding missing tests, refactoring tests; no production code change)
• chore: (updating grunt tasks etc; no production code change)

Test/ Verification

I created two users: SUPER ADMIN and VIEWER:

• SUPER ADMIN created base, table and the form; also configured SMTP
• VIEWER opened FORM and enabled "E-mail me at ..." switch
• confirmed, that now there is no error and the switch state saved (if fails in master)
• confirmed, that email is actually sent

[CLAassistant]

All committers have signed the CLA.