GRAILS-11354 GRAILS-11179 - Improve GrailsParameterMap handling for data binding

This reverts commit 498853e4aca0efefd6c8a4e1a2befe8da77896f8.

Conflicts:
	grails-test-suite-web/src/test/groovy/org/codehaus/groovy/grails/web/binding/GrailsParameterMapBindingSpec.groovy