Rework `MessageFormatter` to use a match method in the same way as
`FunctionProvider` does.
Added GET `MessageFormatter` to gitdemo model.
refs #41
Added user code section for imports in `FunctionProviders`
Also code formatting.
Added user code section for imports in generic formatter code template
Refactor Endpoint code template to move MF and FP matching code to
methods.
Change Generic Formatter code template to use the new match method
Formatting using Eclipse built-in formatter
Added `@generated` tags to XmlFormatter methods