feat(oauth): support passing key content or file paths for OAuth1a keys

[ctasada]

Allow OAuth1aConfig to accept encryption and signature keys as either file paths or direct content strings.

Validate at least one is provided for each key type.

[bfoz]

I only skimmed the changes, so apologies if this should be obvious... Does this change how the environment variables work?

For running in a container, it would be useful to be able to set the environment variables to the key contents instead of a file path.

[ctasada]

@bfoz It doesn't touch the env variables at all, in fact that could be a potential improvement: add the env variables to set them. Those new variables are totally optional.

My use case is that I need to provide the keys to a service. Having only support for files is not convenient, since adds a lot of complexity. Having variables with the file content simplifies a lot the implementation.

[Voyz]

Hey @ctasada thanks for this addition and appreciate you providing extra context on your pain point here. It is well implemented; I'd just follow through with @bfoz's suggestion to make these settable as env vars, as this would be consistent with other settings in this repository. Do you think you could add these before we merge?

[ctasada]

@Voyz I will add them later today

[ctasada]

@Voyz done. PTAL

[Voyz]

LGTM thanks @ctasada great contribution 🙌

[Voyz]

Released as v0.1.22: https://github.com/Voyz/ibind/releases/tag/v0.1.22