chore(content-server): clean up backbone code for simple routes

[LZoog]

Because:

• Now that we've rolled out the simple routes to 100%, we want to clean up the remaining backbone code.

This commit:

• Removes all mustache files associated with the simple routes (cannot_create_account, clear_storage, cookies_disabled, legal, and tos)
• Removes all view js files (cannot_create_account, clear_storage, cookies_disabled, tos)
• Removes all test spec files (cannot_create_account, clear_storage, cookies_disabled, tos)
• Removes references to the Backbone views from the router file

Closes FXA-7398

---

The original PR for this was here. I've opened this one to get a fresh review. I also filed this ticket in case we want to build these pages similarly.

[nx-cloud]

☁️ Nx Cloud Report

CI is running/has finished running commands for commit b54fc50. As they complete they will appear below. Click to see the status, the terminal output, and the build insights.

📂 See all runs for this branch

---

✅ Successfully ran 7 targets

• nx affected --base=main --head=b54fc50d91ee90dd1bc5d506d44dd80f3dcab54d --parallel=1 -t test-unit
• nx affected --base=main --head=b54fc50d91ee90dd1bc5d506d44dd80f3dcab54d --parallel=1 -t compile
• nx run-many -t copy-gql
• nx run-many -t extract-gql
• nx affected --base=main --head=b54fc50d91ee90dd1bc5d506d44dd80f3dcab54d --parallel=3 -t lint
• nx affected --base=main --head=b54fc50d91ee90dd1bc5d506d44dd80f3dcab54d --parallel=3 -t compile
• nx run-many --parallel=1 -t build --projects=fxa-shared,fxa-auth-client,fxa-react

---

Sent with 💌 from NxCloud.

[LZoog]

🥴 I thought I confirmed the string extraction test failure was no longer an issue here but I'm not seeing that it was ran. I'll take a closer look at it tomorrow.

[clouserw]

😍

[LZoog]

🎉 Huzzah, fxa-l10n was successfully added by the script after tracking down the issue (commented in script). I'm going to open a separate PR for it and once it's merged I'll rebase here.

edit: see #15571, once that's merged I will revert some of these changes and rebase

[bcolsson]

From what I can tell, only text is being removed. So approving. (Please let me know if I'm overlooking something.)

Also, thanks for finding the source of the error in the action script!

[vbudhram]

@LZoog Very nice!