feat(toolsets): add support for multiple toolsets in configuration (#323)

Users can now enable or disable different toolsets either by providing
a command-line flag or by setting the toolsets array field in the TOML
configuration.

Downstream Kubernetes API developers can declare toolsets for their
APIs by creating a new nested package in pkg/toolsets and registering
it in pkg/mcp/modules.go

Signed-off-by: Marc Nuri <marc@marcnuri.com>

internal/test/test.go

@@ -0,0 +1,8 @@
+package test
+
+func Must[T any](v T, err error) T {
+	if err != nil {
+		panic(err)
+	}
+	return v
+}