Versioning removes openapi tags / tag metadata.

[jterblanche]

Describe the bug
Firstly a HUGE thanks for this.
Using tag metadata as per Metadata and Docs URLs
When implementing VersionedFastAPI, original openapi tags / tag metadata disappear from openapi.json

To Reproduce

from fastapi import FastAPI
from fastapi_versioning import VersionedFastAPI
import uvicorn

tags_metadata = [
    {
        "name":"root",
        "description":"Root description here" 
    }
]
original_app = FastAPI(title="Items API", description="API for Items in the database.",  openapi_tags=tags_metadata)
@original_app.get("/", tags=["root"])
def root():
    return {"root":"hello"}

versioned_app = VersionedFastAPI(original_app, version_format='{major}', prefix_format='/v{major}', enable_latest=True, openapi_tags=tags_metadata)

if __name__== "__main__":
    uvicorn.run(original_app, host="0.0.0.0", port=8000)
    # uvicorn.run(versioned_app, host="0.0.0.0", port=8000)

If you run uvicorn.run(original_app, host="0.0.0.0", port=8000), Root description here appears in openapi.json as expected.
If you run uvicorn.run(versioned_app, host="0.0.0.0", port=8000), Root description here disappears from openapi.json

Expected behavior
Expected openapi tags to carry over to versioned api.

Additional context
Thanks for the versioning module - aside from this issue it has been awesome!