Add support for accessing Secret Manager secret versions

[owainhunt]

Adds support for hitting the projects.secrets.versions.access endpoint of the Secret Manager REST API. This is just one endpoint of a larger API, but is one of the most useful endpoints to hit from a server application.

[owainhunt]

cc @Andrewangeta

[Andrewangeta]

@owainhunt Looks good to me! @jordanebelanger did you wanna try to add the refreshing protection in so we could get all that plus this API out at once?

[owainhunt]

Just added some more error types. @Andrewangeta any progress on getting this merged in?

[Andrewangeta]

@owainhunt Sorry about getting this behind man 😭. I don't mind merging this in and then doing a separate release with improvements if you need this ASAP. Time is no where to be found but I will be on holiday starting next week and that should help give me time to catch up.

[owainhunt]

@Andrewangeta not a problem 🙂 we've been using the fork internally, and I'm on holiday now anyway, so no great rush if there are other things you want to get in with this one.

[flopshot]

@owainhunt I tried your fork today and it works with my project perfectly.

[owainhunt]

@Andrewangeta any chance of getting this merged in?

[flopshot]

@Andrewangeta any chance of getting this merged in?

I've been using this fork for a few months now. Still working as expected.

[Andrewangeta]

Yea I've been behind and this for a while now and let's get this merged in now and we'll do more significant changes like I was planning later on when time permits.