core-*-api: backport support for external route ref default targets + config route binding

[Rugvip]

Hey, I just made a Pull Request!

The new frontend system supports route binding through static configuration, for example:

app:
  routes:
    bindings:
      catalog.createComponent: catalog-import.importPage

It also lets you define default targets for external route references, for example:

export const registerComponentRouteRef = createExternalRouteRef({
  optional: true,
  defaultTarget: 'catalog-import.importPage',
});

This adds support for both of these features in the existing frontend system.

✔️ Checklist

• A changeset describing the change and affected packages. (more info)
• Added or updated documentation
• Tests for new functionality and regression tests for bug fixes
• Screenshots attached (for UI changes)
• All your commits have a Signed-off-by line in the message. (more info)

[backstage-goalie]

Changed Packages

Package Name	Package Path	Changeset Bump	Current Version
example-app	packages/app	none	v0.2.98-next.1
@backstage/core-app-api	packages/core-app-api	patch	v1.12.5
@backstage/core-compat-api	packages/core-compat-api	patch	v0.2.6-next.0
@backstage/core-plugin-api	packages/core-plugin-api	patch	v1.9.2
@backstage/plugin-api-docs	plugins/api-docs	patch	v0.11.6-next.0
@backstage/plugin-catalog-graph	plugins/catalog-graph	patch	v0.4.6-next.0
@backstage/plugin-catalog	plugins/catalog	minor	v1.20.1-next.1
@backstage/plugin-org	plugins/org	patch	v0.6.26-next.0
@backstage/plugin-scaffolder	plugins/scaffolder	minor	v1.20.2-next.1

[github-actions]

This PR has been automatically marked as stale because it has not had recent activity from the author. It will be closed if no further activity occurs. If the PR was closed and you want it re-opened, let us know and we'll re-open the PR so that you can continue the contribution!

[freben]

nice

[github-actions]

Thank you for contributing to Backstage! The changes in this pull request will be part of the 1.28.0 release, scheduled for Tue, 18 Jun 2024.