TT-1188 mdcb testing framework / Gw refactor

[sredxny]

Description

refactor GW in order that we can run multiple instances as objects via code (not docker, not binaries), added method to run gw in testing mode as a worker node. Created gw object that wrapps some information and methods specific for a gateway instance. This must be merged in tandem with:

• https://github.com/TykTechnologies/tyk-analytics/pull/2166
• https://github.com/TykTechnologies/tyk-sink/pull/109

Related Issue

https://tyktech.atlassian.net/browse/TT-1188

Motivation and Context

Created the proper structure so we can run integration tests for MDCB environment

How This Has Been Tested

• Run Gw
• Run GW instances from MDCB testing framework

Screenshots (if appropriate)

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Refactoring or add test (improvements in base code or adds test coverage to functionality)

Checklist

• Make sure you are requesting to pull a topic/feature/bugfix branch (right side). If pulling from your own
  fork, don't request your master!
• Make sure you are making a pull request against the master branch (left side). Also, you should start
  your branch off our latest master.
• My change requires a change to the documentation.
  • If you've changed APIs, describe what needs to be updated in the documentation.
  • If new config option added, ensure that it can be set via ENV variable
• I have updated the documentation accordingly.
• Modules and vendor dependencies have been updated; run go mod tidy && go mod vendor
• When updating library version must provide reason/explanation for this update.
• I have added tests to cover my changes.
• All new and existing tests passed.
• Check your code additions will not fail linting checks:
  • go fmt -s
  • go vet

[matiasinsaurralde]

Looks good, we need to fix the conflicts.

[padiazg]

LGTM

[tbuchaillot]

LGTM