Allow configuring collection no-items text via manifest or attribute

[nathanwoulfe]

This PR introduces the ability to provide custom text for the no-items message in a collection, either via the collection extension manifest or collection configuration object.

To test via manifest:

• edit /src/packages/members/member-group/collection/manifests.ts
  • add noItemsLabel: 'Custom text' to the meta property
• verify the member group collection displays 'Custom text' in the empty state,
• edit the manifest again
  • update noItemsLabel to #general_delete
• verify the member group collection displays the localized text in the empty state

To test via config:

• edit /src/packages/dictionary/dashboard/dictionary-overview-dashboard-element.ts
  • add a config attribute to the umb-collection element: .config=${{ noItemsLabel: 'Custom text'}}
• verify the dictionary/translation section dashboard displays 'Custom text' in the empty state
• edit the element again
  • update noItemsLabel to #general_delete
• verify the dictionary/translation section dashboard displays the localized text in the empty state

If both the manifest and element config set the noItemsLabel property, the manifest value is prioritised. If neither is set, we fallback to the original No items text, via the collection_noItemsTitle localization key.

[Copilot]

Pull Request Overview

This PR enables custom configuration of the no-items text in a collection by allowing the label to be set via the collection manifest or an element's configuration.

• Added an optional noItemsLabel property to both the collection configuration and manifest meta interfaces.
• Updated the default collection element to dynamically generate the empty state label from the manifest, config, or fallback localization key.

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
src/Umbraco.Web.UI.Client/src/packages/core/collection/types.ts	Added the optional noItemsLabel property to the collection configuration interface.
src/Umbraco.Web.UI.Client/src/packages/core/collection/extensions/collection.extension.ts	Extended the manifest meta interface by adding an optional noItemsLabel property.
src/Umbraco.Web.UI.Client/src/packages/core/collection/default/collection-default.element.ts	Introduced a helper method to determine the empty state label using manifest, config, or fallback localization.

Comments suppressed due to low confidence (1)

src/Umbraco.Web.UI.Client/src/packages/core/collection/default/collection-default.element.ts:73

• [nitpick] Consider checking if the noItemsLabel value starts with '#' to determine whether it should be interpreted as a localization key. If not, returning the provided custom text directly instead of passing it to this.localize.string could prevent unnecessary localization lookups.

const labelKey = this.#collectionContext?.manifest?.meta.noItemsLabel ??

[Copilot]

Pull Request Overview

This PR introduces the ability to configure custom "no-items" text for collections using either the extension manifest or a configuration attribute, with the manifest value taking precedence over the configuration if both are provided. Key changes include:

• Adding a new noItemsLabel property to the collection configuration interface.
• Extending the manifest's metadata to include noItemsLabel.
• Implementing and using a helper method to determine and render the appropriate empty state label.

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
src/Umbraco.Web.UI.Client/src/packages/core/collection/types.ts	Added noItemsLabel property to the collection configuration interface.
src/Umbraco.Web.UI.Client/src/packages/core/collection/extensions/collection.extension.ts	Added noItemsLabel to the manifest metadata type.
src/Umbraco.Web.UI.Client/src/packages/core/collection/default/collection-default.element.ts	Introduced a helper method to generate the empty state label based on manifest or config, and updated the render method accordingly.