Is your feature request related to a problem or challenge? Please describe what you are trying to do.
I have a need to create array builders for many different types and then add some number of nulls to them. I noticed that only some builder types support append_nulls.

Describe the solution you'd like
I'd like it if there was an efficient way to add many nulls to my builder. Some builders expose an add_nulls method (like BooleanBulder for example), while others do not, including:

• FixedSizeBinaryDictionaryBuilder
• FixedSizedBinaryBuilder
• GenericBytesBuilder
• GenericListBuilder
• StructBuilder

Describe alternatives you've considered
call append_null many times.

for _ in 0..n {
  builder.append_null();
}

Additional context