Add join module

pkg/container/batch/batch.go

pkg/hash/joingroup.go

pkg/hash/types.go

pkg/sql/colexec/hashgroup/group.go

pkg/sql/colexec/hashjoin/join.go

pkg/sql/colexec/hashjoin/types.go

pkg/sql/colexec/limit/limit.go

pkg/sql/colexec/mergesum/summarize.go

pkg/sql/colexec/output/output.go

pkg/sql/colexec/projection/projection.go

pkg/sql/colexec/restrict/restrict.go

pkg/sql/colexec/summarize/summarize.go

pkg/sql/colexec/top/top.go

pkg/sql/colexec/top/types.go

pkg/sql/colexec/unittest/projection_test.go

pkg/vm/pipeline/pipeline.go

pkg/vm/process/types.go