feat: fix for issues related with hitting limit of sqlalchemy pool + TCP connections for

[ikondrat]

What has changed and why?

This is PR fixes 2 issues because they are both about hitting limits. Depending on system state and it is one of them:

• Hitting the limit or parallel TCP connections
  OSError: [Errno 24] Too many open files
• Hitting the limit of sqlalchemy pool connections
  sqlalchemy.exc.TimeoutError: QueuePool limit of size 5 overflow 10 reached,

Fix for this is:

• increase pool size for sqlalchemy to 60
• define concurrency parameters for uvicorn server, with defining

How has it been tested?

Check #212 to reproduce the issue

and follow the same steps on this PR, the issue should not be reproduced anymore

[michal-lightly]

LGTM!