gopls/tsprotocol: make Disabled in CodeAction optional
gopls/tsprotocol: make Disabled in CodeAction optional

The new LSP stubs were returning a "disabled" struct in CodeActions,
which is wrong, and this CL fixes.

Tested by hand.

Fixes golang/go#55080

Change-Id: Id38df18f1e3f20ef2aa1cb1adfe96dacacad9ad6
Reviewed-on: https://go-review.googlesource.com/c/tools/+/431216
TryBot-Result: Gopher Robot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Run-TryBot: Peter Weinberger <dd140fb9530d791057dd8833ea6768ff65fcde71@google.com>
gopls-CI: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>
Reviewed-by: Robert Findley <9179eee875d1ee628c37fb47d7e749e855ffd21f@google.com>

golang/tools,golang/tools,golang/tools,golang/tools,golang/tools