Add text extraction based on ToUnicode cmap

Cargo.toml

@@ -34,6 +34,7 @@ serde = { version = "1.0", features = ["derive"], optional = true }
 time = { version = "0.3", features = ["formatting", "parsing"] }
 tokio = { version = "1", features = ["fs", "io-util"], optional = true }
 weezl = "0.1"
+rangemap = "1.5"
 
 [dev-dependencies]
 clap = { version = "4.0", features = ["derive"] }