Grafana-CLI: Wrapper for grafana-cli within RPM/DEB packages and config/homepath are now global flags (#17695)

* Feature: Introduce a grafana-cli wrapper

When our users install the *nix packed version of grafana, tendency is to use the services and scripts installed as part of the package for grafana-server. These leverage the default configuration options by specifying the several default paths.

This introduces a similar approach for the grafana-cli binary. We exposed it through a wrapper to ensure a proper configuration is in place. To enable that, we add the .real suffix to the original binary (grafana-cli.real) and then use a bash script named grafana-cli as the wrapper.

* Make the config and homepath flags global

* Introduce `configOverrides` as a global flag

This flag allows us to pass configuration overrides as a string.

The string follows the convention of configuration arguments separated by a space e.g. "cfg:default.paths.data=/dev/nullX cfg:default.paths.logs=/dev/nullX"

Also, it is backwards compatible with similar the previous configuration method through tailing arguments. Tailing arguments take presedence over the configuration options string.

* Only log configuration information in debug mode

* Move the grafana-cli binary to $GRAFANA_HOME/bin

As part of the package install process, we copy all the release files and
directories into the grafana home directory. This includes the /bin folder
from where we copied the binaries into their respective destinations.
After that, the /bin folder gets deleted as we don't want to keep
duplicates of the binaries around.

As part of this commit, we moved the re-creation of /bin within
grafana-home and the copy of the original binary (again) after the
folder gets deleted.

pkg/cmd/grafana-cli/main.go

@@ -51,6 +51,18 @@ func main() {
 			Name:  "debug, d",
 			Usage: "enable debug logging",
 		},
+		cli.StringFlag{
+			Name:  "configOverrides",
+			Usage: "configuration options to override defaults as a string. e.g. cfg:default.paths.log=/dev/null",
+		},
+		cli.StringFlag{
+			Name:  "homepath",
+			Usage: "path to grafana install/home path, defaults to working directory",
+		},
+		cli.StringFlag{
+			Name:  "config",
+			Usage: "path to config file",
+		},
 	}
 
 	app.Before = func(c *cli.Context) error {