Add attributes for categories in all views

[hxii]

• [X] I have read this document: https://miniflux.app/opinionated.html#feature-request

Currently, when looking at the Categories view, items have the following aria label:

<a href="/category/2/entries" aria-label="Category: 💻 Tech">💻 Tech</a>

This makes it very convenient to style posts in certain categories using attr selectors in CSS. Unfortunately, this is not present in the History and Unread views:

<a href="/category/2/entries">💻 Tech</a>

Would be awesome if this attribute (and attributes in general) could be added across the board.