The main motivation behind this is simplicity and correctnes, but the new small config library is also faster:
```
BenchmarkDefaultConfigProvider/Viper-16 252418 4546 ns/op 2720 B/op 30 allocs/op
BenchmarkDefaultConfigProvider/Custom-16 450756 2651 ns/op 1008 B/op 6 allocs/op
```
Fixes#8633Fixes#8618Fixes#8630
Updates #8591Closes#6680Closes#5192
This commit pulls most of the image related logic into its own package, to make it easier to reason about and extend.
This is also a rewrite of the transformation logic used in Hugo Pipes, mostly to allow constructs like the one below:
{{ ($myimg | fingerprint ).Width }}
Fixes#5903Fixes#6234Fixes#6266
