Added Rust crates script

Necessary to implement the installation of Rust and associated crates
which can be used by downstream configurations. This functionality was
originally part of the macOS Configuration project but has been moved
here to provide a common foundation in which to build upon.

lib/verifiers.sh

@@ -126,3 +126,20 @@ verify_path() {
   fi
 }
 export -f verify_path
+
+# Checks for missing Rust crates.
+verify_rust_crates() {
+  printf "\nChecking Rust crates...\n"
+
+  local crates="$(ls -A1 $HOME/.cargo/bin)"
+
+  while read line; do
+    if [[ "$line" == "cargo install"* ]]; then
+      local crate=$(printf "$line" | awk '{print $3}')
+      verify_listed_application "$crate" "${crates[*]}"
+    fi
+  done < "$MAC_OS_CONFIG_PATH/bin/install_rust_crates"
+
+  printf "Rust crates check complete.\n"
+}
+export -f verify_rust_crates