Add view and submission events to /company page

The purpose of this issue is to add structured events to the /company page for both free and trial registration flows. This will allow us to build funnels and understand how many get to this step.

Structured events to be added:

category	action	Label	Additional context to capture	Notes (reference for this issue, not an actual snowplow event property)
Registrations::CompanyController	render	free_registration OR trial_registration	GitLab User ID	Event fires when the page loads.
registrations:company:new	click_trial_toggle	On OR OFF	GitLab User ID	Event fires when a user is on the free_registration flow and the user toggles the trial toggle on or off with the label value capturing the state the toggle was changed to. Note: This is a front end event
Registrations::CompanyController	successfully_submitted_form	free_registration OR trial_registration	GitLab User ID	User clicks continue on the company page

Self-describing event tracking to be added:

• Form change tracking