Standardize context for input and chaining

[Nuru]

what

• Refine the context object concept:
  • The previous context output contained normalized and generated data. This has now been renamed normalized_context
  • The new context object output simply propagates the input unmodified
  • The new context.tf file can be dropped into any module to provide standard context inputs and a context output (module.this.context) that can be fed into other modules
• Refine the id length limit:
  • Rename id_max_length to id_length_limit
  • Prevent consecutive delimiters and at the same time ensure that if the id is truncated, it is truncate to exactly id_length_limit characters
• Ensure that it is possible to eliminate delimiters by setting delimiter = "". Closes Empty delimiter does not work with TF 0.12 #77
• Add additional tests for all of the above.

why

• Provide a consistent interface to our modules, allow chaining, and provide something like a global setting as requested in Make var.label_order "global" #88
• Make length limit for id more intuitive. Since id is also used as a tag value, and AWS limits tag value length to 255 characters, limit the id length by default so it will not break AWS.
• Some environments do not allow non-alphabetic characters in names
• Greater code coverage for testing helps prevent bugs from creeping in as new features are added

[Nuru]

/test all