Come up with a way to provide default keys for a map based on the type of the key where multiple keys required

[knovichikhin]

Come up with a way to provide default keys for a map based on the type of the key where multiple keys required.

Most resent attempt:

#76

service-model-swift-code-generate/Sources/ServiceModelGenerate/ServiceModelCodeGenerator+createStructureStubVariable.swift

Lines 179 to 186 in 65e5e80

	if requiredSize == 1 {
	let defaultKeyValue = getDefaultValue(type: keyType, fileBuilder: fileBuilder)
	mapConstructor.append("\(defaultKeyValue): \(defaultValue)")
	} else {
	for index in 0..<requiredSize {
	mapConstructor.append("\"Entry_\(index)\": \(defaultValue)")
	}
	}

The branch handling requiredSize > 1 can be improved by handling enum cases and values other than strings.