Deploy PR Azure Functions into their Target Environment

[noce2]

The environment of an Azure Function is currently dictated by the combination of variables set in a yaml file environment and the secrets variable group. At the moment all PRs are by default set to non-production. The scope of this story is to enable the capability to set the environment of a PR to the master branch to the pre-production values. This will give an early indication of whether the pre-prod environment will be stable with the new code, prior to making any merges to master.
Code segment:

user-account-service/azure-pipelines.yml

Line 28 in 8184e95

- ${{ if contains(variables['Build.SourceBranchName'], 'merge') }}: # only works if you have a PR branch

The current integration tests also run against a non-prod configured version of the API exposed via the gateway. The scope of this story is to create a new pre-prod test api that contains the right request signing config for the pre-prod environment.
Code segment:

user-account-service/azure-pipelines.yml

Line 131 in 8184e95

npm test -- --world-parameters {\"baseFunctionUri\":\"https://mathdojoio.cloud.tyk.io/user-account-service-np-test/api\",\"apiKey\":\"\"}

A/C:

1. The azure pipelines yaml is modified to use the pre-production secrets and environments if the PR target branch is master.

2. The integration tests against a pre-prod deployed function run via a new API created on the api gateway.