add function `set_x method` with (start: f64, end: f64) to make better experience for set_x(&self, &PlotBounds)

[chanmaoganda]

Is your feature request related to a problem? Please describe.

When developing with egui 0.34, it makes mad when i only need to change x while i need to pass the whole struct

Describe the solution you'd like

add a method of set_x_bound(&self, start: f64, end: f64) to do things in set_x(&self, &Self)

Describe alternatives you've considered

Additional context

[chanmaoganda]

btw, add a function to provide x range with simply (f64, f64) for easier unpack is kinda of better?

get x range by min()[0] and max()[0] or by range_x() to get the rangeInclusive is annoying

i'm new to egui, sorry for my misunderstardings

[chanmaoganda]

willing to make pull requests for adding utility functions mentioned above