Move tests for params trailing comma to the test gen tool

src/params/default/arrow-function.template

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

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

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

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

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

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

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

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

src/params/default/func-decl.template

src/params/default/func-expr.template

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

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

src/params/default/gen-meth.template

src/params/default/meth.template

src/params/trailing-comma-dflt-param.case

src/params/trailing-comma-multiple-param.case

src/params/trailing-comma-rest-early-error.case

src/params/trailing-comma-single-param.case

...xpressions/arrow-function/params-trailing-comma-length.js