* Support both integer and string keys in anchored keys
* Podlang parser support for records
* Validate record usage in Podlang
* Lower records to middleware
* Cross-module record imports
* Tidying
* Record entry name literal
* More tidying
* More tests, make sure qualified record literals are supported
* Use snake-case for record entry names
* Review feedback
- Introduce a new operation ReplaceValueWithEntry that allows taking any statement and replacing literal arguments with entries given a matching Contains statement.
- Allow entries as args in custom statements
- Circuit optimization: For the public statements slots in the circuit we only support None and Copy which take at most 1 argument; but we were still doing max_statement_args random accesses per slot; so I reduced that to just 1 random access to a previous statement.
Adds nicer errors for Podlang code, using the `annotate_snippets` crate, the same crate used by the Rust compiler to generate contextual errors. This prints a short snippet of the code containing the error within the error message, highlighting the part that needs to be fixed.
It also includes a change to the `load_module` function, changing a `Vec` function argument to a slice.
