Add an endpoint to return TSD Token

[a-ghanem]

Describe the pull request:

• Functional change

Pull request long description:

Added a new REST API endpoint to return a TSD token.

[kjellp]

@joshbaskaran do you think this PR is possible to get updated, reviewed and merged relatively quickly, or do you foreseen some trouble here? It would possibly speed up uploads quite a bit, and maybe get us beyound the 2hrs token expiry problem we're facing currently.

[joshbaskaran]

@kjellp
I would prefer to change the end-point to /tsd/token instead.
Other than that I'm quite sure how this would resolve a token expiry issue. I would like some context here like who/what is consuming this end-point and how its used.

[kjellp]

The name change of end-point should not be a show-stopper, only need to update our lega-commander code to use that instead (currently the -b option of upload command is using the gettoken endpoint of the proxy service.

After lc swaps the LS AAI token for a TSD token, that TSD token has a TTL of ~24 hrs instead of ~2 hrs for the LS AAI token. But we need to double check that this also holds for a folder upload with many files (and that not a LS AAI token based "init" communication with the proxy service is needed for each of the files in the folder upload).

And to enable this "direct TSD upload pattern" using the -b option and the gettoken endpoint, also requires a closer inspection of the resume functionality, that we don't immediately break that.... (it's working for individual files now (via proxy service uploads), but not for folders...)

[joshbaskaran]

@kjellp
In that case, please feel free to merge the branch :)

As in the comment earlier, we do the namechange in proxy end-point and lega-commander in sync (new card added by Parisa in the board)

[Parisa68]

@dependabot rebase