Factor out RecordService component, in prep for enabling recording services in database

[kevinrobinson]

This is part of #115 and #5.

This refactors the UI code for recording a new service into its own component and adds some basic specs for it.

No visual or functional regressions (although "Save" is still intentionally disabled until the backend pieces are ready):

This also led to some cleanup in InterventionsDetails, which can ultimately be simplified or factored further as part of the additional steps in #115.

[kevinrobinson]

@BWieber this is the first piece of the UI code for #115.

Also, this uses the following placeholder ids for the service_types right now:

{
  502: 'Attendance Officer',
  503: 'Attendance Contract',
  504: 'Behavior Contract',
  505: 'Counseling, in-house',
  506: 'Counseling, outside',
  507: 'Reading intervention',
  508: 'Math intervention'
}

You can use the same values on the server side and things will just work, or if you end up using different values that's cool and I can update these ids later to match. 👍 either way!