WIP [Rust SDK] Add the Cargo workspace, Gradle integration and model crate

[prodriguezdefino]

First change in the series that adds the Apache Beam Rust SDK.

This change adds:

• The Cargo workspace at sdks/rust (rustfmt and clippy configuration, workspace lints, dev profiles) with a single member.
• apache-beam-model: protobuf and gRPC bindings generated at build time from the model protos in this repository (model/pipeline, model/fn-execution, model/job-management).
• Gradle integration (:sdks:rust), so the SDK builds like the rest of the repository: build, check (rustfmt + clippy -D warnings), test, fmt and clean. build.gradle applies one script per build area from sdks/rust/gradle/; the tasks call cargo, which handles incremental builds. Gradle passes the Beam version from gradle.properties to cargo; no Beam version is hard-coded in the Rust sources.
• Release tooling: release/src/main/scripts/set_version.sh bumps the Cargo manifests through sdks/rust/scripts/set_version.sh.
• local-env-setup.sh installs Rust and protoc.
• README.md and docs/development.md.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 58.78%. Comparing base (9685063) to head (b81ba09).
⚠️ Report is 106 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff              @@
##             master   #40508      +/-   ##
============================================
+ Coverage     58.65%   58.78%   +0.12%     
- Complexity    13843    13922      +79     
============================================
  Files          2579     2585       +6     
  Lines        270366   271702    +1336     
  Branches      11212    11244      +32     
============================================
+ Hits         158587   159713    +1126     
- Misses       105747   105987     +240     
+ Partials       6032     6002      -30     

Flag	Coverage Δ
java	65.27% <ø> (+0.19%)	⬆️
python	79.70% <ø> (-0.16%)	⬇️

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[CH-Abhinav]

Hey @prodriguezdefino, I would like to help this PR as much as possible since I didn't know Beam is getting a Rust SDK. I am new to beam and I am excited to see Rust based work here.

I tested this branch locally on Windows with rustc 1.98 and protoc 36.0 — cargo check built cleanly and all proto/gRPC definitions generated without issues.

One small note: building on Windows requires protoc in PATH (or setting the PROTOC environment variable). Would it be helpful to add a quick mention in docs/development.md regarding installing protoc on Windows (e.g., via winget install Google.Protobuf or manual binary download)?

Happy to help test upcoming PRs on Windows or contribute to the downstream crates as the SDK progresses.