Introduce RelationshipByIdSeekPipe
Rename starting pipes and add tests
Support for relationship by id seeks in Ronja except that rel patterns don't yet go through it

o Introduce SemanticQuery that encapsulates semantic state information for Ronja
o Introduce AstAnnotator facade that constructs SemanticQuery
o Change nameMatchPatternElements to only rewrite the patterns in a MATCH clause
Merge pull request #2109 from boggle/2.1-rel-id-start

Preliminary support for relationship by id seeks in Ronja