Add property-get utility function

This function will look for a given property in a given table. It gives
back either the property, or an explanation of why it could not be
retrieved.

Cargo.toml

@@ -10,6 +10,7 @@ itertools = "0.10.0"
 reqwest = { version = "0.11.13", features = ["json", "stream", "multipart"] }
 serde = { version = "1.0.152", features = ["derive"] }
 tokio = { version = "1.24.2", features = ["macros", "rt-multi-thread"] }
+toml = "0.5"
 
 # Packages available in Debian (Sid)
 # clap = "4.5.23"