Ajax: move ajax event aliases to their own file

Fixes #15126
Ajax: Support usage without jQuery.event

Fixes #15118
Closes gh-1588
Wrap: Declare a dependency on the manipulation module

Fixes #15121
Closes gh-1589
Core: Work around loss of precision from parseFloat

Fixes #15100
(cherry picked from commit b6e99eb43c35a3cd048c5c56d31c7e871f299a77)
Tests: Clean up isNumeric tests
(cherry picked from commit d05f4bda1cc0b1ef76dce41a53c17f75c105a377)