Do not assume dictionaries exists in footer

[pcjentsch]

This is my first Rust PR, please let me know if I could do this in a more idiomatic way!

Which issue does this PR close?

Closes #1335, on the arrow-rs side at least, Julia's Arrow.jl also writes mismatched versions (apache/arrow-julia#320).

What changes are included in this PR?

IPC reader no longer assumes footer exists.

Are there any user-facing changes?

No.

[viirya]

dictionaries is not a required field in the footer. This looks good fix.

[viirya]

There are some format error.

[codecov-commenter]

Codecov Report

Merging #1631 (86cf000) into master (7d00e3c) will increase coverage by 0.00%.
The diff coverage is 73.07%.

@@           Coverage Diff           @@
##           master    #1631   +/-   ##
=======================================
  Coverage   83.02%   83.03%           
=======================================
  Files         193      193           
  Lines       55577    55580    +3     
=======================================
+ Hits        46145    46149    +4     
+ Misses       9432     9431    -1     

Impacted Files	Coverage Δ
arrow/src/ipc/reader.rs	89.27% <73.07%> (-0.10%)	⬇️
arrow/src/array/transform/mod.rs	86.68% <0.00%> (-0.12%)	⬇️
parquet/src/encodings/encoding.rs	93.56% <0.00%> (+0.18%)	⬆️
parquet_derive/src/parquet_field.rs	66.43% <0.00%> (+0.22%)	⬆️
arrow/src/datatypes/datatype.rs	66.80% <0.00%> (+0.39%)	⬆️

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[viirya]

You can run cargo fmt locally to check the format. There are also some clippy error. You can click the CI check links to see the details too.

[pcjentsch]

thank you, should be good now!

[viirya]

Thank you @pcjentsch

[alamb]

❤️