Adapt slide-in forms to use the new `IxChainedSlideInService`

Use the new service to open slide-in forms. Make multiple PRs (maybe one for 3-4 modules) so regressions can be avoided while testing. Keep in mind

• Use the new `ix-modal-header2` for slide-in form headers with the IxChainedSlideInService

• You can use the import
  `@Inject(SLIDE_IN_CLOSER) protected slideInCloser$: Subject<unknown>`
  to get the subject that you can call next on to initiate the closure of the slide-in form.

• It can be used like so to open a new slide-in form