Issue #2987964 by smustgrave, pminf, manuel.adan, maboresev, kishor_kolekar, benjifisher, rkoller, Chris Matthews, Sutharsan, xjm, Amber Himes Matz, AaronMcHale, larowlan, tim.plunkett, tedbow, catch: Move custom block types admin link to admin/structure

Issue #2960978 by maboresev, benjifisher: Change getSourceIDsHash to getSourceIdsHash in the Migrate module