refactor!: rename get_result to to_sketch

[tisonkun]

cc @PsiACE @notfilippo

[Copilot]

Pull request overview

This PR performs a breaking refactor to improve API consistency by renaming the get_result method to to_sketch for union types. The change affects both HllUnion and CpcUnion, aligning their method names with a clearer, more descriptive convention.

Changes:

• Renamed HllUnion::get_result() to HllUnion::to_sketch()
• Renamed CpcUnion::get_result() to CpcUnion::to_sketch() (introduced with new CPC sketch support)
• Updated all test files and documentation to use the new method name

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
datasketches/src/hll/union.rs	Renamed method from get_result to to_sketch and improved documentation with a period at the end of the summary line
datasketches/src/cpc/union.rs	Renamed method from get_result to to_sketch and added comprehensive documentation with examples
datasketches/src/hll/mod.rs	Updated module-level documentation example to use to_sketch
datasketches/tests/hll_union_test.rs	Updated all test cases to use to_sketch instead of get_result
datasketches/tests/cpc_union_test.rs	Updated all test cases to use to_sketch instead of get_result
CHANGELOG.md	Documented the breaking change for HllUnion and the new CpcUnion feature

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[PsiACE]

lgtm