Merge tag '3.3' into develop

Bump to 3.3.0

New units:
* Frequency (@bretthysuik)
* Electric resistance (@bretthysuik)
* Electric current (@bretthysuik)
* Electric potential (@bretthysuik)
* Power (@bretthysuik)
* Level (@bretthysuik)
* Power ratio (@bretthysuik)
* Amplitude ratio (@bretthysuik)
* Acceleration (@derekhe)

Improvements:
* Support logarithmic units in generator scripts
* Improve readability in ToString(). Use digit grouping in fixed point notation. Use scientific notation for values below 1e-3 and from 1e6 and up.
build: Fix nuget publish scripts

Locate the non-symbols .nupkg file and publish that one. The
.symbols.nupkg file will automatically be pushed to symbols server
along with it.
build: Use full path in nuget-publish.ps1