Support additional issuers for generated certificates

[MxFr]

These changes allowed me mitigate #194 and use the LetsEncrypt staging environment.

Adding the new service IAdditionalIssuersSource looked like the most flexible solution opposed to a list of certificates in the LettuceEncryptOptions and allows to combine different approaches.

[codecov[bot]]

Codecov Report

Merging #207 (efc2186) into main (cd68f74) will decrease coverage by 0.24%. The diff coverage is 0.00%.

@@            Coverage Diff             @@
##             main     #207      +/-   ##
==========================================
- Coverage   45.94%   45.69%   -0.25%     
==========================================
  Files          44       44              
  Lines        1110     1116       +6     
==========================================
  Hits          510      510              
- Misses        600      606       +6     

Impacted Files	Coverage Δ
.../LettuceEncrypt/Internal/AcmeCertificateFactory.cs	0.00% <0.00%> (ø)
src/LettuceEncrypt/LettuceEncryptOptions.cs	100.00% <ø> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update cd68f74...efc2186. Read the comment docs.

[natemcmaster]

Changes look fine to me. Did you consider writing a unit test for the new code?

[MxFr]

A unit test will probably be a good idea, but I will need some time to think on how to test it properly.

I think since the PfxBuilder is created by the CertificateChainExtensions in a extension method I dont think I can mock it. So I'd need to use a mock client returning a certificate with an issuer that is not supported and a IAdditionalIssuersSource that supplies that issuer.

I might manage it in the next few days.

[natemcmaster]

Any progress on unit tests? Writing tests on this code can be hard. Did you at least do some manual testing on this?

[github-actions[bot]]

This pull request appears to be stale. Please comment if you believe this should remain open and reviewed. If there are no updates, it will be closed in 14 days.

[github-actions[bot]]

Thank you for your contributions to this project. This pull request has been closed due to inactivity.