MDL-23692: forgot pw - move request handling to fn
MDL-23692: forgot pw - move confirmation handling
MDL-23692: forgot pw: add token management table
MDL-23692: forgot pw: move function to lib
MDL-23692: forgotpw - remove redundant code
MDL-23692: forgotpw: comments & layout changes

no functional change
MDL-23692: forgotpw: better failure notices
MDL-23692: Forgotpw - move redirection logic to fn
MDL-23692: Forgotpw: simplify forgotpw process
MDL-23692: Forgotpw: coding styletidyups
MDL-23692: Forgotpw: coding style tidyups 2