use value class to improve StyledComponent constructor time

[wagyourtail]

I noticed while profiling that it was taking a significant amount of time to construct components on one of my projects with a very large dom.

by very large I mean

this improvement is achived by making the delegate for refreshOnUpdate a value class, and directly supplying the delegate when there is no initial value. therefore allowing for less class construction and storing of the delegate classes.

before:

after:

profiling was done on Chrome on my linux desktop.

[wagyourtail]

second commit fixed that I missed value on Style's refresh delegate.

I haven't changed my codebase otherwise, idk why the profiler is missing StyledComponent's inner constructor on the After in the original after screenshot

[rjaros]

Great improvement! Thank you!