Replaced automattic tracks cocoa pod with automattic track SPM

[charliescheer]

Fix

Simplenote iOS is currently using tracks version 0.13, which is a little old... Tracks stopped supporting cocoa pods on version 2 as well. So it seemed like a good idea to update to using the SPM version of tracks and get onto the newest release. In this PR I have done that.

Relies on #1545

Test

(Required) List the steps to test the behavior. For example:

1. pull the branch and run rake dependencies on the repo to update the pods
2. make sure the app can build
3. Trigger a trackable event (like opening the sidebar or making a note)
4. Go to tracks live, wait a while, and then confirm your event comes through. Be aware that you can't filter SN events by user id, so you will have to find it manually

Review

(Required) Add instructions for reviewers. For example:

Only one developer is required to review these changes, but anyone can perform the review.

[wpmobilebot]

You can test the changes in simplenote-ios from this Pull Request by:

• Clicking here or scanning the QR code below to access App Center
• Then installing the build number pr1549-48b47a0-018d1471-8bc8-470d-8b05-5a728e65db95 on your iPhone

If you need access to App Center, please ask a maintainer to add you.

[peril-automattic]

	Warnings
⚠️	PR is not assigned to a milestone.

Generated by 🚫 dangerJS

[jleandroperez]

I LOVE this PR!!!

sir!!

[charliescheer]

Merging this even though the UI Tests are failing. Will look into those in a future PR