feat: added `<select>` data instruction

added `!select` yaml tag
fix: improved fn JSON schema

fix: clearer errors for prohibited properties with `transitions` property
fix: removed `!fn` yaml tag
fix: use `module: nodenext` in tsconfig

fix: Enable merge `<<` support for YAML.

This is officially a YAML 1.1 features, but very useful for scenarios.

fix: `!required` tag without type specification

fix: remove `!required` property from `$ref` when normalizing schema

fix: implicitly accept data functions in sub schemas

fix test

fix: missing `description` property for end state

fix: update @letsflow/jmespath to v1.1.5-jasny.1

fix: export `applyFn`

fix: normalize schema `allOf` in combination with `properties`

fix: actor and schema JSON schema

fix: validation error when using a service without explicit notify