feat(back-button): add 'backButtonDefaultHref' property to IonicConfig

[EinfachHans]

Pull request checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been reviewed and added / updated if needed (for bug fixes / features)
• Build (npm run build) was run locally and any changes were pushed
• Lint (npm run lint) has passed locally and any fixes were made for failures

Pull request type

Please check the type of change your PR introduces:

• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes
• Other (please describe):

What is the current behavior?

Issue Number: #19305

What is the new behavior?

• add 'backButtonDefaultHref' property to IonicConfig

Does this introduce a breaking change?

• Yes
• No

Other information

[brandyscarney]

Thank you for the PR! We've discussed this and will be adding it, but at the moment we're focused on getting some fixes in so this will have to be open for a bit until we decide to do a feature release.

[liamdebeasi]

Looks good! Can we just fix that merge conflict?

[brandyscarney]

I pushed some fixes for this so it would work with Angular. The react-router package needs to be updated to include this. I'll be looking into this soon. You can test it out with Angular using the following dev build:

npm i @ionic/angular@5.1.0-dev.202004241700.c6dee23 --save

[brandyscarney]

This is ready to merge now! Thanks for working on this. 🙂