Add field descriptions to data structures and turn on validation in Swagger Gen

[peterbroadhurst]

firefly-transaction-manager/pkg/fftm/api_test.go

Lines 262 to 268 in a87fcb8

	func TestSwaggerEndpoints(t *testing.T) {
	// TODO: Add field descriptions
	// testDescriptions = true
	// defer func() {
	// testDescriptions = false
	// }()

Found during implementation of #85