Composite field with bitmap. Spec Builder.ImportJSON/ExportJSON

[Andrei-cloud]

Implementing missing composite with bitmap specification Builder.ImportJSON and ExportJSON

to be able to have composite fields specification defined with field bitmap:

{
	"name": "TEST Spec",
	"fields": {
		"1": {
			"type": "Composite",
			"length": 255,
			"description": "Private use field",
			"prefix": "ASCII.LL",
			"bitmap": {
					"type": "Bitmap",
					"length": 8,
					"description": "Bitmap",
					"enc": "HexToASCII",
					"prefix": "Hex.Fixed",
					"disableautoexpand": true
			},
			"subfields": {
				"1": {
					"type": "String",
					"length": 2,
					"description": "Cardholder certificate Serial Number",
					"enc": "ASCII",
					"prefix": "ASCII.Fixed"
				},
                      // other subfields

[alovak]

@Andrei-cloud thanks for the PR! It looks good. I'll solve the issue with the linter and I think we can merge your suggested changes. I'll give it one more look shortly.

[mfdeveloper508]

#285