Add a form field that allows to add preset regular expressions

It could be useful to have a wizard page that would help in creating a replacement rule, maybe through some choices presented by third-party modules.

Just to make an example, if there is a "Custom filter - Wikipedia" project, it could add some presets like "Wikipedia links", "Wikipedia headers", "Wikipedia footers". In this way, the users would not be forced to accept a filter created by a module, but would be helped in adding some replacement rules; they would be free to add more rules that are not releated with the module which adds those presets.