mod+tlv: add new Blob type alias, add go.work

In this commit, we add a new type alias for a blob type. This type can be used in areas where a byte slice is used to store a TLV value, which may be a fully opaque nested TLV.

We also commit our go.work file to ensure the changes that follow can always build.

Author: Roasbeef

go.work

@@ -0,0 +1,6 @@
+go 1.22.0
+
+use (
+	.
+	./tlv
+)