Use BufferBuilder in parquet instead of custom ScalarBuffer

[tustvold]

Is your feature request related to a problem or challenge? Please describe what you are trying to do.

The existence of the custom ScalarBuffer in the parquet crate is primarily because I wasn't aware of BufferBuilder at the time I wrote it. With some relatively minor additions to BufferBuilder the parquet crate could make use of it.

Describe the solution you'd like

• Add a doc comment pointing users of MutableBuffer to BufferBuilder
• Add as_slice, as_mut_slice and resize APIs to BufferBuilder
• Create dedicated BooleanArrayReader for parquet, as bool: ArrowNativeType
• Remove parquet's ScalarBuffer

Describe alternatives you've considered

We could not do this

Additional context

#1820 added a different ScalarBuffer abstraction to arrow, this is a bit of a confusing situation and we should just remove the version from parquet.