Update NGINX One API doc titles

[mjang]

Several instances of "NGINX One console" should be changed to "NGINX One Console" in https://docs.nginx.com/nginx-one/api/api-reference-guide/, per our style guide.

Originally posted by @mjang in #521 (comment)

[mjang]

Credit: community contribution from @Kkresge in #521

[JTorreG]

I thought this had been resolved already. can you confirm @mjang ?

[mjang]

They were only partially resolved. However, I'd call this a p4 bug, since the problem is now limited to description fields