Add timestamp logicaltype

[claudevdm]

Add timestamp logical type as described in https://s.apache.org/beam-timestamp-strategy

• This new logical type is not yet added to

  beam/model/pipeline/src/main/proto/org/apache/beam/model/pipeline/v1/schema.proto

  Line 117 in 2c2211e

  enumEnum {

• It is not yet supported by other SDK's (only java)

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[claudevdm]

R: @ahmedabu98
R: @Abacn
R: @damccorm

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[claudevdm]

/gemini review

[gemini-code-assist]

Code Review

This pull request introduces a new Timestamp logical type, which is a great addition for handling timestamps with configurable precision in Beam schemas. The implementation is solid and the accompanying tests are very thorough, covering a wide range of positive, negative, and edge cases. I have a couple of suggestions to improve the implementation's readability, maintainability, and performance, mainly around avoiding magic numbers for field access and replacing Math.pow with a more efficient alternative.

[damccorm]

Thanks!