prefix params cases to dflt- while templates are not set to dlft anymore

src/params/dflt-ref-prior.case

src/params/dflt-ref-self.case

src/params/dflt-rest.case

src/params/error/arrow-function.template

src/params/error/cls-decl-gen-meth-static.template

src/params/error/cls-decl-gen-meth.template

src/params/error/cls-decl-meth-static.template

src/params/error/cls-decl-meth.template

src/params/error/cls-expr-gen-meth-static.template

src/params/error/cls-expr-gen-meth.template

src/params/error/cls-expr-meth-static.template

src/params/error/cls-expr-meth.template

src/params/error/func-decl.template

src/params/error/func-expr.template

src/params/error/gen-func-decl.template

src/params/error/gen-func-expr.template

src/params/error/gen-meth.template

src/params/error/meth.template

src/params/syntax/arrow-function.template

src/params/syntax/cls-decl-gen-meth-static.template