Add stamp attribute in go_binary rule

[TennyZhuang]

What version of rules_go are you using?

0.19.0

What version of gazelle are you using?

commit: 7a19100a6d86a392a2f88e337fbcc60a3e4b154a

Near master

What version of Bazel are you using?

0.24.1

Does this issue reproduce with the latest releases of all the above?

Yes

What operating system and processor architecture are you using?

Linux amd64

What did you expect to see?

Hope the stamp behavior to keep consistent with other language toolchains in https://docs.bazel.build/versions/master/be/overview.html

Many [lang]_binary rule have stamp attribute.

[jayconrod]

Context: in #2110, we started respecting the --stamp command line flag. Previously, we stamped unconditionally if x_defs referenced a variable from the workspace status script. Now, we only stamp when --stamp is set.

cc_binary and other rules have a stamp attribute which can be set to -1 (default; observe --stamp flag), 0 (never stamp), or 1 (always stamp). We could have something similar, though it's not clear to me that 0 is meaningful, since we could just not set x_defs.