fix: ISSUE-639 enabled reuse of https sockets in the aws-sdk

[Zambonilli]

Issue #, if available:
ISSUE-639
Description of changes:
Enabled the reuse of https sockets in all lambdas in the aws-sdk.

Checklist:

• Have you successfully deployed to an AWS account with your changes?

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[rsmayda]

Thanks for submitting could you update the branch to be in line with develop?

Also could you add a bit to this PR description on how this variable will be used?

[Zambonilli]

AWS_NODEJS_CONNECTION_REUSE_ENABLED is used by the nodejs aws-sdk to indicate that it should create and use https socket pool instead of creating a new https socket on every aws-sdk service request. The environment variable is documented in documentation for nodejs considerations in the aws-sdk here.