fix(stackable-webhook): Explicitly set the TLS provider for the ServerConfig, and enable "safe" protocols

[NickLarsenNZ]

Rustls now requires a global provider to be set, or explicitly passed in via the server/client config.

Normally this would be set by the application, and not in a library, however this library is to remove so much boiler plate from our applications.

Description

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# Author
- [ ] Changes are OpenShift compatible
- [ ] CRD changes approved
- [ ] Integration tests passed (for non trivial changes)

# Reviewer
- [ ] Code contains useful comments
- [ ] (Integration-)Test cases added
- [ ] Documentation added or updated
- [ ] Changelog updated
- [ ] Cargo.toml only contains references to git tags (not specific commits or branches)

# Acceptance
- [ ] Feature Tracker has been updated
- [ ] Proper release label has been added