[THREESCALE-10934] [3scale_batcher] Update regex to match key with special chars

[tkan145]

What

Fix https://issues.redhat.com/browse/THREESCALE-10934

Dev notes

In my opinion there are 2 ways to fix this:

1. Replace the current regrex with the regrex from porta repo. The allowed key formats are describe in the linked JIRA. I don't like this approach because we always have to make sure that the APIcast regular expression matches the one from the porta. Also, the current code allows set keys of any format but restricting the format when get is also strange to me.
2. Allow everything except spaces and let porta handle the validation during the authorization call. I think this is a better option but would be happy to discuss further.

Verification Steps

• Configure a single Product A with user_key

  aGVsbG93b3JsZAo=

• Configure batcher policy with the following:

  { "name" : "apicast.policy.3scale_batcher", "configuration" : { "batch_report_seconds" : 1 } }

• Start dev environment

  make development
  make dependencies

• Run apicast locally

  THREESCALE_DEPLOYMENT_ENV=staging APICAST_LOG_LEVEL=debug APICAST_WORKER=1 APICAST_CONFIGURATION_LOADER=lazy APICAST_CONFIGURATION_CACHE=0 THREESCALE_PORTAL_ENDPOINT=https://token@3scale-admin.example.com ./bin/apicast

• Run query with the valid user_key

  
  # capture apicast IP
  APICAST_IP=$(docker inspect apicast_build_0-development-1 | yq e -P '.[0].NetworkSettings.Networks.apicast_build_0_default.IPAddress' -)

curl -v -k -H "Host: example.com:443" "http://${APICAST_IP}:8080/?user_key=aGVsbG93b3JsZAo="

* Check that `credentials not found` error does not appear in the log. For example:

reports_batcher.lua:99: get_all(): failed to get report for key service_id:12,user_key:aGVsbG93b3JsZAo=,metric:Hits err: credentials not found, context: ngx.timer, client: 10.10.10.1, server: 0.0.0.0:8080