feat: add google analytics config

[Marianarodrigues7]

This PR adds google analytics configuration to extension.

Events added to analytics:

Event name	Event description	Parameters
page_view	Event when extension opens	version
extension_error	Event when unhandled rejection	error reason
number_of_keys	Event triggered in each store update	total (key list length); session (session items length); cookie (cookie items length); local (local items length);
view_value	Event when clicking view value
copy_value	Event when clicking copy value
set_value	Event when clicking set value
delete_item	Event when clicking delete key
invalid_form	Event when clicking save key, in add key form, with incorrect fields	invalidFields (stringified list of incorrect fields)

[JPedroBorges]

Added the following events:

• set_value: when user sets a value
• copy_value: when a user copies a value
• number_of_keys: number of keys that each user is saving
• page_view:
  • Extension page: with the app version
• extension_error
  • unhandled exceptions: exception reasons

[JPedroBorges]

As discussed offline, added the following metrics

• view_value: when user sees value
• delete_item: when users deletes an item
• invalid_form: when the user doesn't fill correctly the form
• number_of_keys: number of keys that each user is saving, grouping by type

[JPedroBorges]

@Marianarodrigues7 LMK if there's something else we should add in this scope 👍🏻