This PR adds support for static frameworks with multiple architectures. If a static framework contains multiple architectures, input arguments to libtool do not have path extensions (contrary to static libraries, where .a is always used). XCRemoteCache to recognize input files by expecting '.a` extension. To support a case for static frameworks, this PR adds the same behavior where a file with no extension is passed.

In this PR, an E2E test to cover a scenario described in #184 is added:

• For the StandaloneSampleApp, a new static farmework StaticFramework is added
• In an E2E flow, an extra step added to validate compilation of the StaticFramework for WatchOS simulator
• By the way, fixing an E2E script to fail an xcodebuild step. Previously, failed xcodebuild was not propagated, because | tee .. was swallowing an error.

Refactoring&Fix summary:

• Introduce mutant for #185 #186 is a draft PR that demonstrates a failure in E2E scenario before applying a fix
• 8201f77 is an actual fix for [WatchOS] 'Producer' mode failed with static framework #184

Fixes #184