Support DataType::Dictionary in make_builder within struct_builder.rs

[kszlim]

Is your feature request related to a problem or challenge? Please describe what you are trying to do.
Make it so that dictionary encoded sub-builders can be constructed from Fields.

Describe the solution you'd like
As described above

Describe alternatives you've considered
n/a

Additional context
I don't see any reason why it's unsupported besides it just not being feature complete yet.

[tustvold]

The challenge with dictionaries is the combinatorial explosion of possible types, we don't want to pay the codegen and consequently compile time costs for hundreds of different combinations of dictionary builder, when frankly very few of them make a whole lot of sense.

Might I suggest we just cover the cases with Int32 keys, and values of Utf8, LargeUtf8, Binary and LargeBinary.

[kszlim]

@tustvold made the PR as you've suggested, feel free to make any edits you need (or i can do them).

[alamb]

label_issue.py automatically added labels {'arrow'} from #6593