Create a TowerClient

[Vince-janv]

Write a client to interact with the seqera-platfrom/NFTower API

It needs:

• Authentication
• launch via workflow/launch or action/launch

Instantiation:

• An API-token is needed in the config
• The base-URL for the API

[islean]

Basing this comment off of #4204 (comment).

Parts of the client

My thinking is that we need

• A prod user which has a created token which we add to the CGConfig. This token should be sent as a header in any request.
• A stage user which has a created token which we add to the CGConfig. This token should be sent as a header in any request.
• An action per workflow gathering common parameters
  • Specifies github repository
  • Revision
  • PreRunScript (activating the correct conda env etc)
  • computeEnvId
  • pullLatest
  • Potentially params and config which is not case specific (might be more work than gain though)
• Support for POST /action/launch
• Support for GET /workflow/<workflowId>/launch to get the sessionId.
• The base URL in the CGConfig