added metric for number of total responses

[xinau]

Motivation

The ability to calculate the ratio of errors to total number of requests. see #90.

What

This PR adds a new metric for reporting the total number of requests that where made in a addition to the number of failed requests.

How

This was done similar to the number of failed requests.

Verification Steps

A new metric keycloak_response_total should be reported.

Checklist:

• [x] Code has been tested locally by PR requester
• [ ] Changes have been successfully verified by another team member

Progress

• [x] Finished task

[xinau]

@pb82 I hope I'm not bothering, but any chances that we could get this merged soonish? :)

[pb82]

@xinau Sorry for the late response. I will release within this week and try to include your PR. Thanks!

[xinau]

@pb82 Thanks.