feat(formly): add formly-next entry point with ngx-formly v7 support

[chintankavathia]

Introduce @siemens/element-ng/formly-next as a separate secondary entry point supporting @ngx-formly/core v7. This enables standalone component usage without NgModules, improved tree-shaking through provider-based configuration, and alignment with modern Angular patterns.

The existing @siemens/element-ng/formly entry point remains v6-compatible. Both SiFormlyComponent and SiFormlyModule are marked as deprecated with guidance to migrate to SiFormlyNextComponent when upgrading to v7.

Before (v6 — @siemens/element-ng/formly):

  import { SiFormlyModule } from '@siemens/element-ng/formly';

  @NgModule({
    imports: [SiFormlyModule.forRoot()]
  })
  export class AppModule {}

After (v7 — @siemens/element-ng/formly-next):

  import { SiFormlyNextComponent } from '@siemens/element-ng/formly-next';

  @Component({
    imports: [SiFormlyNextComponent]
  })
  export class MyComponent {}

---

Documentation.
Examples.
Dashboards Demo.
Playwright report.

Coverage Reports:

• charts-ng
• dashboards-ng
• element-ng
• element-translate-ng
• maps-ng
• native-charts-ng

[gemini-code-assist]

Code Review

This pull request upgrades @ngx-formly to version 7 and introduces SiFormlyNextComponent as the new component for this version, while deprecating the existing SiFormlyComponent and SiFormlyModule. The application configuration and examples have been updated to use the new component and the provideFormlyCore provider. Feedback includes a request to apply ChangeDetectionStrategy.OnPush to the new component per the style guide and to remove a redundant commented-out import in the app configuration.

[spike-rabbit]

I am a little divided here:
Can we wait until v50 an then just fully update to formly@7?

Or this there a way, where we can still have the same 6 and 7 with the exact same entry point and code?