Add Schema::with_metadata and Field::with_metadata

[alamb]

Which issue does this PR close?

Re #1091

Rationale for this change

It is annoying to add metadata to Fields (and to a lesser degree Schemas)

What changes are included in this PR?

1. Add Schema::with_metadata and Field::with_metadata
2. Update code to use with_metadata which I think is much nicer

Are there any user-facing changes?

New functions

[alamb]

these changes I think show the improved API: no more mut during construction of a Schema

[codecov-commenter]

Codecov Report

Merging #1092 (dfbeb22) into master (e8cc39e) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #1092   +/-   ##
=======================================
  Coverage   82.31%   82.31%           
=======================================
  Files         168      168           
  Lines       49383    49380    -3     
=======================================
  Hits        40649    40649           
+ Misses       8734     8731    -3     

Impacted Files	Coverage Δ
arrow/src/datatypes/field.rs	54.10% <100.00%> (+0.42%)	⬆️
arrow/src/datatypes/mod.rs	100.00% <100.00%> (ø)
arrow/src/datatypes/schema.rs	73.45% <100.00%> (+0.50%)	⬆️
arrow/src/ipc/convert.rs	94.38% <100.00%> (+0.18%)	⬆️
arrow/src/util/integration_util.rs	68.53% <100.00%> (-0.13%)	⬇️
arrow/src/array/transform/mod.rs	84.86% <0.00%> (+0.13%)	⬆️
parquet_derive/src/parquet_field.rs	66.21% <0.00%> (+0.22%)	⬆️

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[alamb]

Since there are no objections or comments, merging this one in

[alamb]

Related to #1091