Closes #1902: Print the original and projected RecordBatch in dynamic_types example

[martin-g]

Which issue does this PR close?

Closes #1902.

Rationale for this change

The user can get a feeling of the data.

What changes are included in this PR?

Are there any user-facing changes?

[codecov-commenter]

Codecov Report

Merging #1903 (f6d1160) into master (fc4044f) will decrease coverage by 0.00%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #1903      +/-   ##
==========================================
- Coverage   83.43%   83.42%   -0.01%     
==========================================
  Files         203      203              
  Lines       56969    56969              
==========================================
- Hits        47531    47528       -3     
- Misses       9438     9441       +3     

Impacted Files	Coverage Δ
parquet_derive/src/parquet_field.rs	65.75% <0.00%> (-0.46%)	⬇️
arrow/src/datatypes/datatype.rs	65.42% <0.00%> (-0.38%)	⬇️

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[alamb]

Thanks @martin-g and @paddyhoran !