Improved dictionary invariants

[jorgecarleitao]

This PR changes the internal invariant from DictionaryArray to only contain keys that:

• can be casted to usize
• the maximum value is smaller than the values' length

This allows removing bound checks when iterating over the values via its keys.

Backward incompatible changes

• DictionaryArray::from_data was replaced by try_new, try_new_unchecked and try_from_keys
• DictionaryKey now only implements NativeType + TryFrom<usize> + TryInto<usize>

[codecov]

Codecov Report

Merging #1137 (a461a93) into main (b3583b6) will increase coverage by 0.03%.
The diff coverage is 78.15%.

@@            Coverage Diff             @@
##             main    #1137      +/-   ##
==========================================
+ Coverage   83.49%   83.52%   +0.03%     
==========================================
  Files         366      366              
  Lines       35635    35799     +164     
==========================================
+ Hits        29752    29902     +150     
- Misses       5883     5897      +14     

Impacted Files	Coverage Δ
src/array/dictionary/iterator.rs	100.00% <ø> (+41.66%)	⬆️
src/array/equal/dictionary.rs	100.00% <ø> (ø)
src/array/equal/mod.rs	80.00% <0.00%> (-3.59%)	⬇️
src/compute/arithmetics/mod.rs	74.10% <ø> (ø)
src/io/parquet/read/statistics/dictionary.rs	48.57% <ø> (ø)
src/compute/cast/dictionary_to.rs	22.41% <7.14%> (-4.40%)	⬇️
src/io/avro/read/nested.rs	64.53% <50.00%> (-0.60%)	⬇️
src/io/parquet/read/deserialize/dictionary.rs	79.06% <65.62%> (-2.69%)	⬇️
src/array/growable/dictionary.rs	77.31% <72.22%> (-0.21%)	⬇️
src/io/json/read/deserialize.rs	72.55% <83.33%> (-0.07%)	⬇️
... and 28 more

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