Improves positional completions added for `sg msp` in #58538 by checking for partial flag input (`-` and `--`), which now complete flags correctly, and also improving the way we build positional argument completions with a more robust helper, `completions.CompletePositionalArgs`.
This change extracts `monitoring` into a submodule for import in `sourcegraph/controller` (https://github.com/sourcegraph/controller/pull/195) so that we can generate dashboards for Cloud instances. These steps were required:
1. Initialize a `go.mod` in `monitoring`
2. Extract `dev/sg/internal/cliutil` into `lib` to avoid illegal imports from `monitoring`
3. Add local replaces to both `sourcegraph/sourcegraph` and `monitoring`
4. `go mod tidy` on all submodules
5. Update `go generate ./monitoring` commands to use `sg`, since the `go generate` command no longer works
6. Update `grafana/build.sh`, `prometheus/build.sh` to build the submodule
7. Amend linters to check for multiple `go.mod` files and ban imports of `github.com/sourcegraph/sourcegraph`
8. Update `sg generate go` to run in directories rather than from root
The only caveat is that if you use VS code, you will now need to open `monitoring` in a separate workspace or similar, like with `lib`.
Co-authored-by: Joe Chen <joe@sourcegraph.com>
Move sg's docgen code into lib/cliutil/docgen for sharing with the mi CLI. In the future we can move other useful utilities for urfave/cli and CLIs in general into this set of subpackages for use in mi.
