internal/pipewire: move test data to files

These get very big later on, and would be painful to represent as the compound literal.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/pipewire/pipewire_test.go

@@ -0,0 +1,17 @@
+package pipewire_test
+
+import (
+	_ "embed"
+)
+
+var (
+	//go:embed testdata/00-sendmsg00-message00-header
+	sendmsg00Message00Header string
+	//go:embed testdata/01-sendmsg00-message00-POD
+	sendmsg00Message00POD string
+
+	//go:embed testdata/02-sendmsg00-message01-header
+	sendmsg00Message01Header string
+	//go:embed testdata/03-sendmsg00-message01-POD
+	sendmsg00Message01POD string
+)