Implement endpoint "GET /tasks/{id}"

[uniqueg]

Is your feature request related to a problem? Please describe. proTES should respond to all TES requests in the most reasonable or helpful way in a spec-conformant way.

In the case of the GET /tasks/{id} endpoint, this simply means to return the requested task's info from the database.

Describe the solution you'd like Return the task info from the database, if available. The solution is almost identical to that for the GET /runs/{run_id} endpoint in WES-ELIXIR, implemented in files:

• https://github.com/elixir-europe/WES-ELIXIR/blob/dev/wes_elixir/ga4gh/wes/server.py
• https://github.com/elixir-europe/WES-ELIXIR/blob/dev/wes_elixir/ga4gh/wes/endpoints/get_run_log.py

Describe alternatives you've considered N/A

Additional context Depends on issue #19 being resolved.