Process receipts emitted from known error signals to print more details for failing sway unit tests

Some known error signals also produce receipts to provide more information like `assert_eq` giving out the values for the non-equal variables detected. We should also add them to have rust's `left : x` but `right: y` like prompts with failing tests with `forc-test`.

related to #3952.

Start by tracing how forc-test processes receipts from known error signals, using the behavior described here and related issue #3952 as context. The work is done when failing Sway unit tests print left and right values for signals such as assert_eq, matching the requested Rust-style details.

Written by the indexing model from the issue text.