Add xtask for finding crates with missing licenses (#11776)

This PR adds a new `cargo xtask licenses` command for finding crates
with missing license files.

A number of crates were uncovered that were missing a license file, and
have had the appropriate license file added.

Release Notes:

- N/A

Cargo.lock

@@ -1887,6 +1887,16 @@ dependencies = [
  "winx",
 ]
 
+[[package]]
+name = "cargo_toml"
+version = "0.20.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c8cb1d556b8b8f36e5ca74938008be3ac102f5dcb5b68a0477e4249ae2291cd3"
+dependencies = [
+ "serde",
+ "toml 0.8.10",
+]
+
 [[package]]
 name = "cast"
 version = "0.3.0"
@@ -12810,7 +12820,9 @@ name = "xtask"
 version = "0.1.0"
 dependencies = [
  "anyhow",
+ "cargo_toml",
  "clap 4.4.4",
+ "toml 0.8.10",
 ]
 
 [[package]]