Dynamically update `fontdict` for `iplt.text`

[ianhi]

Problem

iplt.text doesn't allow functions for fontdict or any other kwargs that should be processed by Text.

Proposed Solution

make fontdict dynamic. This will require parsing the names and finding the approriate set_ methods.

Additional context

Seemed the lesser of two evils to have an incomplete text with the core functionality there (position and string) than to have nothing and wait until we could make the full thing.