[accessibility] Use `<button>` or `role="button"`

[Malvoz]

Currently, the search and cancel buttons are conveyed as links using a screen reader, please consider using <button> instead, per the WAI-ARIA recommendation. Alternatively use role="button".

[Malvoz]

Potentially helpful resources:

• Leaflet guide to accessibility: Test your maps
• Leaflet Plugin Authoring Guide: Content Accessibility