Introduce a BoundedTrie metric which is used to efficiently store and…

[rohitsinha54]

… aggregate a collection of string sequences (FQNs) with a limited size.

It is recommended to review this PR by commits.

BoundedTrie is a space-saving way to store many string sequences (like FQN/file paths). It acts like a tree with branches, holding sequences within a size limit. It can efficiently add, combine, and search and perform trimming of children when the size increases beyond defined max.

Let's say we want to store these sequences, with a size limit of 3:

"folder1/file1.txt"
"folder1/file2.txt"
"folder2/file3.txt"
Here's how the BoundedTrie might look:

root
  - folder1
     - file1.txt
     - file2.txt
  - folder2
     - file3.txt 

If we try to add "folder1/file4.txt", the trie might trim to "folder1", dropping all children to stay within the size limit.

This will be used to replace the StringSet metric for lineage tracking for very large lineage graphs to overcome the size limits.

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[rohitsinha54]

R: @robertwb

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[robertwb]

Same as above.

[rohitsinha54]

@robertwb : Please have another look. Thank you very much.

[rohitsinha54]

This returns a BoundedTrieData over a Set to be consistent with other MetricData in java SDK

[rohitsinha54]

This return a void rather than a reference to updated object because the object is mutable and returning a reference from here will then require unnecessary overhead of using AtomicReference in BoundedTrieCell to safely be able to handle combine call from mutli-threads.