chore: uptake base 0.22.0 and migrate to base-parsing

[deer]

Uptakes base 0.22.0, which introduced several new modules including a generified base-parsing library. The existing Pratt-parser infrastructure in expression-codemodel (ExpressionParser, TemplateParser, Token, Tokenizer, resolvers, tokenparsers — 22 files) was moved to base as part of that release and is now deleted here in favour of the canonical base versions.

Key changes:

• Bump base.version 0.21.5 → 0.22.0
• Delete 22 duplicate parsing classes from expression-codemodel
• Update ExpressionParserTests and TemplateParserTests to use the generified ExpressionParser<N> / TemplateParser<N> APIs from base
• EmptyExpression (codemodel-specific) is retained; empty parse now returns null (base behaviour) instead
• TemplateParser string-literal merging is now supplied as a tryMerge lambda
• Drop base-io (now transitive through base-parsing); suppress dependency analyser warning for base-parsing which must stay compile-scoped for JPMS