Replace rule list with "DSL"

TBD

We can probably just use a triplet of Yul expressions, resp. expression patterns:
- precondition: evaluates to non-zero, if the rule can be applied
- match: pattern expression for matching the rule
- replacement: pattern expression to replace the matched code snippet

The match expression can use symbolic pattern variables for matching variables and constants and (at a later stage when extending this from expressions to statements) arbitrary code blocks. Precondition and replacement expressions can use any pattern variables used in the match expression.

The issue names no files, tests, or entry points and begins with “TBD.” Start by locating the existing rule-list implementation and the Yul expression or pattern handling. The proposed direction mentions precondition, match, and replacement expressions, but the issue provides no acceptance criteria for what done means.

Written by the indexing model from the issue text.