Enhance/tasks-api

[nifedara]

What does this PR do?

Enhances documentation quality

Makes updates to tasks endpoints

• I added response codes and some examples
• I removed trailing slashes from the endpoints
• I updated HTTPException messages to match the error model
• Contributes to resolving this issue: Enhance API documentation and examples hotosm/raw-data-api#219

Consideration :

• For consistency in response, I updated the code for the HTTPException messages to follow the error model. e.g {detail["msg": ""]} instead of just {detail[""]}. I did this without discarding the existing messages
• For endpoints without response examples, I was proactive to hit the endpoint to deduce and create the response examples
• I used black formatter to format the code

How to test?

• Clone this repo
• Follow Docker Installation Guide or local installation guide
• Shoot the server up and view the Documentation changes on your localhost