feat(parser)!: migrate codebase to pest parser

BREAKING CHANGE: changed pipeline delimiter from : to |

Author: lalvarezt-bw

Cargo.lock

@@ -15,3 +15,5 @@ categories = ["text-processing", "command-line-utilities"]
 [dependencies]
 regex = "1"
 clap = { version = "4", features = ["derive"] }
+pest = "2.8"
+pest_derive = "2.8"

Cargo.toml

@@ -6,7 +6,7 @@
 //!
 //! ```rust
 //! use string_pipeline::process;
-//! let result = process("a,b,c", "{split:,:..:join:\\n}").unwrap();
+//! let result = process("a,b,c", "{split:,:..|join:\\\\n}").unwrap();
 //! assert_eq!(result, "a\nb\nc");
 //! ```