add method definition competion

[myroslavarm]

the line
(self methodNames includes: aRBMethodNode) ifFalse: [ ^#() ].
in MatchedNodeProducer >> visitMethodNode: aRBMethodNode
gets rid of the incorrect temp definition completion, but also stops method definitions from being completed. we need to figure out a way to fix it

[MarcusDenker]

This is closed: method definitions are now completed. The workaround stays for not completing temp definitions, which does not work yet

[myroslavarm]

reopened because while the workaround exists method definitions are not completed :(

[myroslavarm]

fixed in this commit : pharo-project/pharo@ddc49cd