skip product fetch when returns to same category

[gibkigonzo]

Related Issues

closes #4066
Related pr: #4077

Short Description and Why It's Useful

This change adds isBackRoute getter which determines if we returned to same route:
page1 => page2 => return to page1 (isBackRoute === true)

And as we have this information we can skip some actions.

Also updated default config for 1.11 (#4072)

Screenshots of Visual Changes before/after (if There Are Any)

Before:

After:

Which Environment This Relates To

Check your case. In case of any doubts please read about Release Cycle

• Test version (https://test.storefrontcloud.io) - this is a new feature or improvement for Vue Storefront. I've created branch from develop branch and want to merge it back to develop
• RC version (https://next.storefrontcloud.io) - this is a stabilisation fix for Release Candidate of Vue Storefront. I've created branch from release branch and want to merge it back to release
• Stable version (https://demo.storefrontcloud.io) - this is an important fix for current stable version. I've created branch from hotfix or master branch and want to merge it back to hotfix

Upgrade Notes and Changelog

• No upgrade steps required (100% backward compatibility and no breaking changes)
• I've updated the Upgrade notes and Changelog on how to port existing Vue Storefront sites with this new feature

IMPORTANT NOTICE - Remember to update CHANGELOG.md with description of your change

Contribution and Currently Important Rules Acceptance

• I read and followed contribution rules

[pkarw]

Great job