MWAA - verify_env - Additional networking checks

[bsajjan]

Issue #, if available:

Description of changes:

• Analyzing route via NAT GW to verify that there is a path to Internet and provide more useful information if the path is incorrect. Added logic to analyze route via Transit GW as well.
• Revised NACL analysis part to handle more sophisticated ACLs
• Revised VPCE analysis part to become more precise
• Made IAM Simulation code more concise
• Switching from IAM Custom Policy Simulation to Principal Policy Simulation as the later addresses cases involving scope/boundary policies.
• Fixes several issues MWAA: Cli returns error when profile contains hyphen #171 MWAA: validation_profile issue when profile contains dash (hyphen) #179 MWAA - Check Service Vpc Endpoints showing wrong results #165 MWAA - IAM Policies validation are showing wrong results comparing with Web version #159

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