angular: Add service method to get locale

When querying the state from the `JsonFormsAngularService` via its `getState` method, the whole state is cloned.
This could lead to performance issues with the angular material renderer set because the `NumberControlRenderer` queried the state on every change detection cycle to get the locale. Thus, the whole state was cloned for every control of these types on every change.
To fix this, the `JsonFormsAngularService` now allows to query the locale directly without cloning the state

* Add method `getLocale` to `JsonFormsAngularService` that does not clone the state
* Use new method in `NumberControlRenderer`

Signed-off-by: Lucas Koehler <lkoehler@eclipsesource.com>

packages/angular-material/src/controls/number.renderer.ts

@@ -25,7 +25,6 @@
 import { ChangeDetectionStrategy, Component } from '@angular/core';
 import { JsonFormsAngularService, JsonFormsControl } from '@jsonforms/angular';
 import {
-  getLocale,
   isIntegerControl,
   isNumberControl,
   or,
@@ -138,7 +137,7 @@ export class NumberControlRenderer extends JsonFormsControl {
       this.max = this.scopedSchema.maximum;
       this.multipleOf = this.scopedSchema.multipleOf || defaultStep;
       const appliedUiSchemaOptions = merge({}, props.config, this.uischema.options);
-      const currentLocale = getLocale(this.jsonFormsService.getState());
+      const currentLocale = this.jsonFormsService.getLocale();
       if (this.locale === undefined || this.locale !== currentLocale) {
         this.locale = currentLocale;
         this.numberFormat = new Intl.NumberFormat(this.locale, {

packages/angular/src/jsonforms.service.ts

@@ -186,6 +186,10 @@ export class JsonFormsAngularService {
         }
     }
 
+    getLocale(): string | undefined {
+        return this._state.i18n?.locale;
+    }
+
     setLocale(locale: string): void {
         this._state.i18n.locale = locale;
         this.updateSubject();