[comm-lib] Hide aws behind a feature flag

Summary: While we used aws dependencies in all services, future diffs will make `comm-lib` a (transitive) dependency of `native_rust_library`. These dependencies aren't needed there so I'm introducing a new feature flag that hides them and the modules that depend on aws crates.

Test Plan: Check that all services compile

Reviewers: bartek, varun, kamil

Reviewed By: bartek, varun

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D10258

services/backup/Cargo.toml

@@ -17,6 +17,7 @@ clap = { version = "4.0", features = ["derive", "env"] }
 comm-lib = { path = "../../shared/comm-lib", features = [
   "http",
   "blob-client",
+  "aws",
 ] }
 once_cell = "1.17"
 tokio = { version = "1.24", features = ["rt-multi-thread", "macros"] }

services/blob/Cargo.toml

@@ -16,7 +16,7 @@ aws-sdk-dynamodb = "0.27"
 aws-sdk-s3 = "0.27"
 chrono = "0.4.31"
 clap = { version = "4.0", features = ["derive", "env"] }
-comm-lib = { path = "../../shared/comm-lib", features = ["http"] }
+comm-lib = { path = "../../shared/comm-lib", features = ["http", "aws"] }
 derive_more = "0.99"
 http = "0.2"
 once_cell = "1.17"