Fix error handler type hint, use flask defined route response types

[Yun-L]

• replaced FlaskResponseType with the ResponseReturnValue type from flask.typing

[gcarvellas]

This does change output when using curl. I'm not sure if this will cause issues when we implement the frontend.

Steps to reproduce:

1. Generate id token. See Write a script to generate a sample id_token #31 for details
2. Set the ID token to a variable token in shell
3. Run the backend and run this command

curl -X GET -H "Authorization: Bearer $token" -H 'Content-Type: application/json' localhost:3001/me

Output before MR:

{
    "name": "test",
    "email": "[email protected]",
    "database": null
}

Output after MR:

"{\"name\": \"test\", \"email\": \"[email protected]\", \"database\": null}"

[gcarvellas]

nevermind. I did a test and this isn't a problem for browsers.

[Yun-L]

did this change the headers in the response? i'm guessing if the headers don't say its a json curl might default to displaying as a string

[gcarvellas]

No it doesn't change the headers. My guess is that json.dumps() changes the formatting to include \

After Changes:

Internal server errorgcarvellas@razer-blade-15:~$ curl -v -X GET localhost:3001/health
Note: Unnecessary use of -X or --request, GET is already inferred.
* processing: localhost:3001/health
*   Trying [::1]:3001...
* Connected to localhost (::1) port 3001
> GET /health HTTP/1.1
> Host: localhost:3001
> User-Agent: curl/8.2.1
> Accept: */*
> 
< HTTP/1.1 200 OK
< Server: gunicorn
< Date: Thu, 14 Sep 2023 18:57:58 GMT
< Connection: keep-alive
< Content-Type: application/json
< Content-Length: 9
< Access-Control-Allow-Origin: *
< 
"\"ok\""

Before Changes:

gcarvellas@razer-blade-15:~$ curl -v -X GET localhost:3001/health
Note: Unnecessary use of -X or --request, GET is already inferred.
* processing: localhost:3001/health
*   Trying [::1]:3001...
* Connected to localhost (::1) port 3001
> GET /health HTTP/1.1
> Host: localhost:3001
> User-Agent: curl/8.2.1
> Accept: */*
> 
< HTTP/1.1 200 OK
< Server: gunicorn
< Date: Thu, 14 Sep 2023 18:58:40 GMT
< Connection: keep-alive
< Content-Type: application/json
< Content-Length: 5
< Access-Control-Allow-Origin: *
< 
"ok"

[gcarvellas]

closing this since we're not using Flask anymore