Add codecs for table def (#133)

pkg/container/nulls/nulls.go

pkg/container/nulls/types.go

pkg/container/vector/vector_test.go

pkg/sql/build/table.go

pkg/sql/colexec/bag/inner/join.go

pkg/sql/colexec/bag/inner/types.go

pkg/sql/colexec/dedup/dedup.go

pkg/sql/colexec/extend/attribute.go

pkg/sql/colexec/group/group.go

pkg/sql/colexec/mergededup/dedeup.go

pkg/sql/colexec/projection/projection.go

pkg/sql/colexec/top/top.go

pkg/sql/compile/compile.go

pkg/sql/compile/inner.go

pkg/sql/compile/projection.go

pkg/sql/compile/refer.go

pkg/sql/op/dedup/dedup.go

pkg/sql/op/group/group.go

pkg/sql/op/innerJoin/join.go

pkg/sql/op/limit/limit.go