feat: add comparison operators to PhysicalNumber

[andreasWallner]

Context, Motivation & Description

In code for checking frequencies/times are in range, e.g. for calculating&checking PLL parameters it's much more readable when PhysicalNumbers can be compared directly and with units, instead of having to go through toBigDecimal.

assert(fdiv_freq < 420MHz)
//vs
assert(fdiv_freq.toBigDecimal < 420000000L)

Impact on code generation

None

Checklist

• Unit tests were added
• API changes are or will be documented:
  • using Scaladoc comments: /** */?
  • on RTD?
  • thanks to a new tracking issue on RTD?

[kleinai]

I think we can merge this without issue if it passes tests.

[kleinai]

I'm going to fix the offending sim code because I wrote it two different ways and I prefer the match-case way instead of the not equal check.

[andreasWallner]

So... with this implementation != null works as required. Removing it was the right thing to do, since HertzNumber and TimeNumber are case classes and have a compiler generated, member equality checking, overridden equals anyways, so mine would never be called...

[numero-744]

How do you think it should be documented? (Do you think it should be?)

[andreasWallner]

How do you think it should be documented? (Do you think it should be?)

I don´t think we need specific documentation, PhysicalUnit is only mentioned in a small subchapter in the documentation - if there is a user who needs the comparison I guess it will just feel naturally?