Problem: usage of `key` and `secret` for bucket configuration is ambiguous

[jraddaoui]

Is your feature request related to a problem? Please describe.

There are a few places where we set up bucket configuration:

• Watcher
• Internal location
• Upload bucket
• Failed buckets

Also in the location configuration stored as JSON in the storage database.

We use "key" and "secret" to configure the credentials, while AWS calls them "Access Key ID" and "Secret Access Key" and MinIO uses "access key" and "secret key".

Describe the solution you'd like

It looks like @sevein already noticed this issue in the https://github.com/artefactual-labs/gotools repository, where we are using AccessKey and SecretKey in the config struct.

https://pkg.go.dev/go.artefactual.dev/tools@v0.16.0/bucket

I'd like to follow that pattern wherever possible.

Additional context

• The upload endpoint was moved in #977, and I took the opportunity to modify those variables in #1016.
• The failed buckets feature is still a WIP #929, but the latest version uses the new naming #930.
• preprocessing-sfa is using the new variable names for the AIS bucket too.