Refactor R client functions for upload requests to include keycloak token

[doulikecookiedough]

To upload data to the vegbank API, users will be required to provide a valid token via keycloak authentication

We also need to provide a path for users to retrieve a valid token - one path we may leverage or build upon is how DataONE currently implements their authentication with R: by having users login via the DataONE search webapp, which provides the token for copy and paste directly into the R client like such:

options(dataone_token = "eyJhbGciOiJSUzI1NiJ9.eyJzdWIiOiJodHRwOlwvXC9vcmNpZC5vcmdcLzAwMDAtMDAwMy0wMDc3...TsnayXOS_PbaFSJ-iowSpX-Q")

DataONE then reads the token from the R options, and we may consider an alternative function like such:

vegbank::set_oidc_token(access, refresh=NULL)

• Note 1: We may want to investigate the usage of oidc as it may be a bit wonky, see Matt's comment below:

metamattj: Or maybe oidc is a bit wonky and this should be named set_token or set_access_token or set_credentials or something more user understandable? I also remembered that we used keyring to securely store keys in the scythe package and it worked well -- might be better than a home-grown credentials store. See https://keyring.r-lib.org/

• Note 2: We currently use httr2 under the hood for vegbankr, which may be useful for what we need, see Jim's comment below:

Jim: I just came across this and haven't really read it yet, but it might be useful: https://httr2.r-lib.org/articles/oauth.html
Note that the vegbankr package is already using httr2 under the hoo
metamattj: There are two big reasons to allow httr2 to manage tokens for you. The first is that httr2 will automatically refresh the token if it’s expired.