add flask.request to the patched objects

[vlabakje]

needed for dash pages functionality

[emillma]

Thanks! This appears to solve the problems with pages.

[mujiannan]

Why not accepted? @snehilvj

[brendanillies]

Agreed that this solves the pages implementation - I neglected to read this issue before reviewing and implementing myself and came to the same conclusion! @snehilvj I'd love to get involved and assist in bringing this library up-to-date with Dash if there is motivation