change hardcoded links in theme pull to use methods to surface urls instead

[FKauwe]

WHY are these changes introduced?

The theme pull command had hardcoded links for previewing your theme, and launching the theme editor.

Fixes #1063

WHAT is this pull request doing?

The hardcoded links were replaced by themePreviewUrl and themeEditorUrl methods.

The themePreviewURL function builds the url following two paths and one path can lead to the url looking slightly different than the original string behavior (it truncates the url if theme.role === live, but I tested both urls in my browser and they went to the same place.
This is the Before + After:
Before:

[1] https://f9e81e-af.myshopify.com/?preview_theme_id=145364484332
[2] https://f9e81e-af.myshopify.com/admin/themes/145364484332/editor

After:

[1] https://f9e81e-af.myshopify.com
[2] https://f9e81e-af.myshopify.com/admin/themes/145364484332/editor

The After is cleaner for this edge case and doesn't add the unnecessary preview part, as the theme is live and the url can point to the live view.

I noticed there were no unittests testing renderSuccess but that other sibling tests do test that and the message surfaced to user, so I added that test

How to test your changes?

• while on main, run p build, then shopify-dev theme pull -e <local-env-name> in external terminal
• choose a live theme to pull to see the edge case
• note the older, longer url surfaced to the user after the renderSuccess message
• pull my branch down locally: fix-hardcoded-links-in-theme-pull
• p build
• run shopify-dev theme pull -e <local-env-name> in external terminal
• note the newer url without the unnecessary preview appended (if you chose a live theme).
• If you choose an unpublished theme to pull the urls remain exactly the same

Measuring impact

How do we know this change was effective? Please choose one:

• n/a - this doesn't need measurement, e.g. a linting rule or a bug-fix

[github-actions]

Coverage report

St.❔	Category	Percentage	Covered / Total
🟡	Statements	78.91%	14556/18447
🟡	Branches	73.24%	7224/9863
🟡	Functions	79.12%	3705/4683
🟡	Lines	79.25%	13762/17365

Test suite run success

3778 tests passing in 1455 suites.

Report generated by 🧪jest coverage report action from b776177

[EvilGenius13]

Thank you for the PR @FKauwe!

[EvilGenius13]

Let's add a patch level changeset. Since the success message used to show ?preview_theme_id when it was a live theme, it's an observable change in the CLI output.

[aswamy]

Tested it out and looks good for live and unpublished themes 👍

Unpublished:

Live: