Move LHOL and LEDA to Cloud9. Update whole lab to use same C9

[switch180]

Issue #, if available:

Description of changes: "Bulletproof" Cloud9 instance launch script. It does the following:

• Auto selects instance VPC subnet based on availability of the customer's preferred instance type
• Bootstraps the instance using a custom User Data script and a SSM document to download the workshop zip
• Empties the S3 bucket on delete to allow stack deletion

Also included are doc changes to reflect use of C9 instance

NOTE For LADV we are still using session manager: we're connecting to the C9 instance in lieu of using the IDE to KISS

Notable changes:

• Python 3.10+ for LEDA thanks to C9
• Move from ALAMI to Ubuntu for LADV
• Sidebar pre text is changed from "Workshop" to the name of the workshop, e.g. LADV
• LGME/LADV/LHOL Cloud9 setup steps in your own account are virtually the same; they all use the same template.

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