Added auto refreshing for 1.x

[edgeinfinity1]

A poll-refreshing implementation for 1.x. I didn't integrate it with realtime since that's a paid extension in 1.x, also it seemingly lacks some apis used by 2.x implementation.

Changes proposed in this pull request:

Reviewers should focus on:

This is quite a rough change, maybe better to add a switch and poll interval setting in the admin page.

Screenshot

Confirmed

• Frontend changes: tested on a local Flarum installation.
• Backend changes: tests are green (run composer test).

Required changes:

• Related Flarum core extension PR's: (Omit this section if irrelevant)