[accessibility] Reset button is missing an accessible name and role="button"

[Malvoz]

• The reset button is missing an accessible name, it is currently announced as "times" or "multiplication" depending on the screen reader. It should have aria-label="Reset".
• The reset button is a link, though it should be conveyed as a button to screen reader users, using role="button".

Potentially helpful resources:

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

[smeijer]

I'd love to accept a pull request for this.

[StellarLogic]

I would love to work on this, can you assign it to me

[smeijer]

I'm not assigning tickets. Please just submit the pull if you're feeling for it. Thanks!