Bump starlette from 0.25.0 to 0.27.0

[pavsorab]

Changes :

• Upgrade starlette version from 0.25.0to 0.27.0
• fastapi is now at 0.95.2 for supporting starlette 0.27.0
• Added h11>=0.13.0 because httpcore 0.17.2 requires h11<0.15,>=0.13
• Added request_body to get the request body directly to allow non-JSON data
• Made changes to tests/unit_tests/test_microservice.py for passing Content-Type as text/plain
• In Swagger UI, users can now enter the body for the request

For performing post requests with request body we must strictly pass headers with Content-Type as text/plain for the request to work. This is to prevent CSRF in FastAPI as mentioned here tiangolo/fastapi#3456 and GHSA-8h2j-cgx8-6xv7

To allow request Body to parse as non-JSON based on media_type the issue is ongoing in tiangolo/fastapi#9159

Fixes #26

Fixes https://github.com/vmware-labs/build-inspector/security/dependabot/5