fix: input should hide when unfocus (#38)

Co-authored-by: Guodong Zang <gdzang@alauda.io>

src/input/tags-input/tags-input.component.ts

@@ -97,7 +97,7 @@ export class TagsInputComponent extends CommonFormControl<string[]> {
 
   get inputClass() {
     return `${this.bem.element('input', {
-      hidden: this.disabled || (!this.snapshot.value.length && !this.focused),
+      hidden: this.disabled || !this.focused,
     })} aui-tag aui-tag--${this.tagSize}`;
   }