[CI] Introduce assign-build:getCurrentVersionInfo
Summary: Get information about the current version (based on git tag)
Test Plan: Got expected result.
Reviewers: ashoat, palys-swm
Reviewed By: ashoat
Subscribers: palys-swm, Adrian, karol-bisztyga, benschac, boristopalov
Differential Revision: https://phabricator.ashoat.com/D2368