[FEATURE] Ability to add Azure DevOps variables as attributes for RP launch

[Shakevg]

Azure DevOps has a lot of variables ()custom or default) that can be useful for RP launch (like Build.BuildNumber, Release.ReleaseId, etc....).
It will be great to have the ability to add it as attributes to RP launch.
The list of variables should be configurable via RP configuration file (some can be added by default).

Note: Variables available via Environment variables.

Example of such variables below:

2021-06-05T09:00:51.1644044Z ##[section]Starting: Initialize job
2021-06-05T09:00:51.1646762Z Agent name: 'Azure Pipelines 2'
2021-06-05T09:00:51.1647444Z Agent machine name: 'WIN-FHM838STKK0'
2021-06-05T09:00:51.2208752Z Environment variables available are below.  Note that these environment variables can be referred to in the task (in the ReleaseDefinition) by replacing "_" with "." e.g. AGENT_NAME environment variable can be referenced using Agent.Name in the ReleaseDefinition: 
				[AGENT_DISABLELOGPLUGIN_TESTFILEPUBLISHERPLUGIN] --> [true]
				[AGENT_DISABLELOGPLUGIN_TESTRESULTLOGPLUGIN] --> [true]
				[AGENT_ENABLETASKRESTRICTIONSTELEMETRY] --> [true]
				[AGENT_HOMEDIRECTORY] --> [C:\agents\2.187.2]
				[AGENT_ID] --> [23]
				[AGENT_JOBNAME] --> [UI tests]
				[AGENT_MACHINENAME] --> [WIN-FHM838STKK0]
				[AGENT_NAME] --> [Azure Pipelines 2]
				[AGENT_OS] --> [Windows_NT]
				[AGENT_OSARCHITECTURE] --> [X64]
				[AGENT_RELEASEDIRECTORY] --> [D:\a\r1\a]
				[AGENT_RETAINDEFAULTENCODING] --> [false]
				[AGENT_ROOTDIRECTORY] --> [D:\a]
				[AGENT_SERVEROMDIRECTORY] --> [C:\agents\2.187.2\externals\vstsom]
				[AGENT_TASKRESTRICTIONSENFORCEMENTMODE] --> [WarningOnly]
				[AGENT_TEMPDIRECTORY] --> [D:\a\_temp]
				[AGENT_TOOLSDIRECTORY] --> [C:\hostedtoolcache\windows]
				[AGENT_VERSION] --> [2.187.2]
				[AGENT_WORKFOLDER] --> [D:\a]
				[AGENTTYPE] --> []
				[BROWSERTYPE] --> [Chrome]
				[BUILD_BUILDID] --> [52149]
				[BUILD_BUILDNUMBER] --> [1.0.52149.1]
				[BUILD_BUILDURI] --> [vstfs:///Build/Build/52149]
				[BUILD_DEFINITIONID] --> [38]

[nvborisenko]

Can be easily implemented as part of https://github.com/nvborisenko/reportportal-extensions-ci extension. This feature will be available for all .net agents.