Move Back button to topbar on Jetpack Connection screens

[robertsreberski]

Related to #101047, #102765
Resolves MYJP-124

Proposed Changes

• Remove back button from Connection screen footer
• Add back button to the compact logo topbar
• Use compact logo & menu in connection screens

Why are these changes being made?

We would like to unify back buttons across different screens in calypso; the approach on moving it to top left corner is used e.g. on WordPress.com pricing page:

We find it a good example and want to get more screens aligned.

Testing Instructions

1. Open Calypso Live, then navigate to /jetpack/connect
2. You should have at least one page in the history (back button active in your browser ui)
3. You should see the following design
4. Clicking the button should navigate you to the previous page; the colors should be aligned with Jetpack design

Pre-merge Checklist

• Has the general commit checklist been followed? (PCYsg-hS-p2)
• Have you written new tests for your changes?
• Have you tested the feature in Simple (P9HQHe-k8-p2), Atomic (P9HQHe-jW-p2), and self-hosted Jetpack sites (PCYsg-g6b-p2)?
• Have you checked for TypeScript, React or other console errors?
• Have you used memoizing on expensive computations? More info in Memoizing with create-selector and Using memoizing selectors and Our Approach to Data
• Have we added the "[Status] String Freeze" label as soon as any new strings were ready for translation (p4TIVU-5Jq-p2)?
  • For UI changes, have we tested the change in various languages (for example, ES, PT, FR, or DE)? The length of text and words vary significantly between languages.
• For changes affecting Jetpack: Have we added the "[Status] Needs Privacy Updates" label if this pull request changes what data or activity we track or use (p4TIVU-aUh-p2)?

[github-actions]

Calypso Live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-144446

Jetpack Cloud live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-144446&env=jetpack

Automattic for Agencies live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-144446&env=a8c-for-agencies

[matticbot]

Here is how your PR affects size of JS and CSS bundles shipped to the user's browser:

Sections (~291 bytes added 📈 [gzipped])

name              parsed_size           gzip_size
jetpack-connect        +516 B  (+0.0%)     +106 B  (+0.0%)
purchase-product       +454 B  (+0.2%)     +218 B  (+0.4%)

Sections contain code specific for a given set of routes. Is downloaded and parsed only when a particular route is navigated to.

Legend

What is parsed and gzip size?

Parsed Size: Uncompressed size of the JS and CSS files. This much code needs to be parsed and stored in memory.
Gzip Size: Compressed size of the JS and CSS files. This much data needs to be downloaded over network.

Generated by performance advisor bot at iscalypsofastyet.com.

[matticbot]

This PR modifies the release build for the following Calypso Apps:

For info about this notification, see here: PCYsg-OT6-p2

• notifications
• wpcom-block-editor

To test WordPress.com changes, run install-plugin.sh $pluginSlug update/jetpack-auth-back-button on your sandbox.

[gmjuhasz]

Works well, nice one!