Add PATCH support to Vault CLI (#17650)

* Add patch support to CLI

This is based off the existing write command, using the
JSONMergePatch(...) API client method rather than Write(...), allowing
us to update specific fields.

Signed-off-by: Alexander Scheel <alex.scheel@hashicorp.com>

* Add documentation on PATCH support

Signed-off-by: Alexander Scheel <alex.scheel@hashicorp.com>

* Add changelog

Signed-off-by: Alexander Scheel <alex.scheel@hashicorp.com>

Signed-off-by: Alexander Scheel <alex.scheel@hashicorp.com>

command/commands.go

@@ -488,6 +488,11 @@ func initCommands(ui, serverCmdUi cli.Ui, runOpts *RunOptions) {
 				BaseCommand: getBaseCommand(),
 			}, nil
 		},
+		"patch": func() (cli.Command, error) {
+			return &PatchCommand{
+				BaseCommand: getBaseCommand(),
+			}, nil
+		},
 		"path-help": func() (cli.Command, error) {
 			return &PathHelpCommand{
 				BaseCommand: getBaseCommand(),