feat(aws-sm): added keychain plugin for aws secret manager

        Primary Change
        ---
        1. Added new package cactus-plugin-keychain-aws-sm under packages/
        2. Added LocalStack under cactus-test-tooling/src/main/typescript for local aws secret manager deployment and testing

        Refactorings that were also necessary to incorporate 1) and 2)
        ---
        3. Updated public-api.ts under packages/cactus-test-tooling/src/main/typescript for exporting the Localstack class, its interface and constants

Resolves #912

Signed-off-by: Jagpreet Singh Sasan <[email protected]>

Author: jagpreetsinghsasan

packages/cactus-plugin-keychain-aws-sm/README.md

@@ -0,0 +1,3 @@
+# `@hyperledger/cactus-plugin-keychain-aws-sm`
+
+## TO-DO