Clean up WORKSPACE.

[mathetake]

Clean up WORKSPACE file:

• move all http_archives to bazel/repositories.bzl
• stop using git_repository for protobuf and proxy_wasm_cpp_sdk
• update cpp_sdk to the latest
• move test/test_data/wasm.bzl to bazel/wasm.bzl

Signed-off-by: mathetake takeshi@tetrate.io

[PiotrSikora]

Looks like rules_rust update resulted in a real issue:

warning: unused variable: `val`
  --> test/test_data/trap.rs:20:28
   |
20 | pub extern "C" fn trigger2(val: i32) -> i32 {
   |                            ^^^ help: if this is intentional, prefix it with an underscore: `_val`
   |
   = note: `#[warn(unused_variables)]` on by default

Could you fix that?

[PiotrSikora]

Nit: I have slight preference for repositories and dependencies instead of dependencies and dependencies_extra.

[PiotrSikora]

Thanks!