Moved proto messages from package wfa.any_sketch to wfa.any_sketch.proto

[brianyi9]

Since we specify a java_package in the proto message, this suggests we may be able to change the package scoping while keeping everyone's java codebases intact, assuming the overrides work the way I think they do as described in https://protobuf.dev/programming-guides/proto3/#packages

Testing

Built with

bazelisk build --config=asan //src/test/...:*
bazelisk build --config=asan //src/main/...:*

Tested with

bazelisk test --config=asan //src/test/...:*

//src/test/cc/any_sketch:aggregators_test PASSED in 0.1s
//src/test/cc/any_sketch:any_sketch_test PASSED in 0.1s
//src/test/cc/any_sketch:distributions_test PASSED in 0.2s
//src/test/cc/any_sketch/crypto:secret_share_generator_test PASSED in 0.3s
//src/test/cc/any_sketch/crypto:shuffle_test PASSED in 0.3s
//src/test/cc/any_sketch/crypto:sketch_encrypter_adapter_test PASSED in 4.3s
//src/test/cc/any_sketch/crypto:sketch_encrypter_test PASSED in 3.0s
//src/test/cc/estimation:estimators_test PASSED in 0.3s
//src/test/cc/math:distributed_discrete_gaussian_noiser_test PASSED in 3.7s
//src/test/cc/math:distributed_geometric_noiser_test PASSED in 7.0s
//src/test/cc/math:noise_parameters_computation_test PASSED in 0.3s
//src/test/cc/math:open_ssl_uniform_random_generator_test PASSED in 0.2s

Executed 12 out of 12 tests: 12 tests pass.

[wfa-reviewable]

This change is