Add support for ParallelCluster 3.7.0

[gmarciani]

Description

Add support for ParallelCluster 3.7.0

Changes

1. pcluster version bumped to 3.7.0 in CloudFormation template and demo env.
2. 3.7.0 features added to feature flags provider + new unit tests covering it.
3. Add Amazon File Cache as a supported shared storage within the Wizard (both frontend and backend changes). This change was considered out of scope at first, but discovered that it was actually easier to introduce it than modifying the inner logic to silently avoid it. Moreover we are providing feature parity for File Cache that is certainly valuable for our users.
4. Documentation: added to DEVELOPMENT.md some valuable information about development process learned during this iteration.

Known Limitations

1. With this change we are not achieving the full feature parity with ParallelCluster 3.7.0. In fact we are missing in the Wizard: support for Ubuntu 22.04 and support for Memory Based Scheduling with Flexible Instance Types. Nevertheless the lack of this feature parity is not a blocker for the wizard.
2. Unit tests for the backend on API GET:/manager/get_aws_configuration have been considered out of scope because they must be written from the ground up and we will cover in a follow up PR.

How Has This Been Tested?

1. Unit tests on the backend
2. Unit tests on the frontend
3. Manual test: created a cluster using a cluster config file exercising all the config-impactful features introduced in ParallelCluster 3.7.0: Ubuntu22.04, Login Nodes, Memory Based Scheduling, Amazon File Cache.

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[mendaomn]

Good job!