fix(email,authentication,forms): email activation bus event pub/sub

[kon14]

Fixes #104.

Authentication's bus subscription to email:status:onConfig no longer triggers its own reconfiguration exclusively on an active Email configuration update, but in any Email config event.
This change is intentional and should pave the way towards Authentication being capable of handling email service going down (due to provider issues for instance as we don't support explicit module deactivation) once we actually introduce any such checks in Email.

Notice: Authentication no longer assumes Email service is available on local auth after #103.

What kind of change does this PR introduce? (check at least one)

• Bugfix
• Feature
• Code style update
• Refactor
• Build-related changes
• Other, please describe:

Does this PR introduce a breaking change? (check one)

• Yes
• No

The PR fulfills these requirements:

• It's submitted to the main branch
• When resolving a specific issue, it's referenced in the PR's title (e.g. fix #xxx, where "xxx" is the issue number)