[Task]: Deduplicate Coders

[Abacn]

What needs to happen?

There are a couple of V2 even V3 coders:

TimerDataCoderV2
MetadataCoderV2
TableDestinationCoderV2
TableDestinationCoderV3

created due to streaming update compatibility concerns. As a tech debt, we should deduplicate them for Beam 3.

Unfortunately we may preserve "V2/V3" suffix in class naming if it is possible to preserve upgrade compatibility, while deduping the (V1)/V2 classes

Issue Priority

Priority: 2 (default / most normal work should be filed as P2)

Issue Components

• Component: Python SDK
• Component: Java SDK
• Component: Go SDK
• Component: Typescript SDK
• Component: IO connector
• Component: Beam YAML
• Component: Beam examples
• Component: Beam playground
• Component: Beam katas
• Component: Website
• Component: Infrastructure
• Component: Spark Runner
• Component: Flink Runner
• Component: Samza Runner
• Component: Twister2 Runner
• Component: Hazelcast Jet Runner
• Component: Google Cloud Dataflow Runner

[Abacn]

This Issue is marked as Beam 3 - Milestone 1: No Code and ML focus. Please help us burning down the open blocker tasks.

• If this issue is solved, close it. If it is obsolete, close as not planned. If it is no longer necessary for Beam 3, move it out of the Milestone.

• If the work is pending, please be reminded that Milestone 1 is targeted for completion by Dec 30, 2025

• If this issue involves multiple milestones (e.g. remove a public API should first mark it as deprecated, scoped in Milestone 1; then finally remove it in Beam 3 release candidate, scoped in Milestone 3) and Milestone 1 portion has completed, consider move the Issue to Milestone 3.

[Abacn]

This is essentially same FR as #18645