Refactor to Vue 3 recommended ESLint rules

These updates ensure better adherence to Vue 3 standards and improve
overall code quality and readability.

- Update ESLint configuration from Vue 2.x to Vue 3 rules.
- Switch from "essential" to strictest "recommended" ESLint ruleset.
- Adjust ESLint script to treat warnings as errors by using
  `--max-warnings=0` flag. This enforces stricter code quality controls
  provided by Vue 3 rules.

tests/unit/shared/Stubs/SizeObserverStub.ts

@@ -8,7 +8,6 @@ export function createSizeObserverStub(
 ) {
   const component = defineComponent({
     name: COMPONENT_SIZE_OBSERVER_NAME,
-    template: `<div id="${COMPONENT_SIZE_OBSERVER_NAME}-stub"><slot /></div>`,
     emits: {
       /* eslint-disable @typescript-eslint/no-unused-vars */
       widthChanged: (newWidth: number) => true,
@@ -19,6 +18,7 @@ export function createSizeObserverStub(
         emit('widthChanged', newValue);
       });
     },
+    template: `<div id="${COMPONENT_SIZE_OBSERVER_NAME}-stub"><slot /></div>`,
   });
   return {
     name: COMPONENT_SIZE_OBSERVER_NAME,