feat(newsletter, contact) strengthen types and remove generics

[hanmindev]

PR Checklist

Please check if your PR fulfills the following requirements:

• [x] The commit message follows our guidelines: https://github.com/graycoreio/daffodil/blob/develop/CONTRIBUTING.md#commit
• [ ] Tests for the changes have been added (for bug fixes / features)
• [ ] Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

[ ] Bugfix
[x] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[ ] Documentation content changes
[ ] Other... Please describe:

What is the current behavior?

Fixes: N/A Touches #1212

What is the new behavior?

Does this PR introduce a breaking change?

[x] Yes
[ ] No

Generics removed from: contact

• DaffContactServiceInterface
• DaffContactSubmit
• DaffContactRetry
• DaffContactActions

newsletter

• DaffNewsletterServiceInterface
• DaffNewsletterSubscribe
• DaffNewsletterRetry
• DaffNewsletterActions
• DaffNewsletterEffects

DaffNewsletterUnion removed. Replaced with more appropriate interfaces for each case

Other information