[REQ] Update go generator to honor type and format for numbers

[cbascom]

Is your feature request related to a problem? Please describe.

When generating go code from an openapi spec built based on the YANG data modeling language, more specific type information is included by specifying both the type and format. I need to be able to generate go code from these specs that uses the correct data types.

Describe the solution you'd like

The code generators already support registering type+format mappings via typeMappings. I would like to expand these mappings for the go generator to include all possibilities for go numeric types.