message: [Swift] Change generated operation classes
diff: @@ -148,7 +148,7 @@ export class SwiftAPIGenerator extends SwiftGenerator<CompilerContext> {
  },
  () => {
  if (source) {
  - this.printOnNewline('public static let operationString =');
  + this.printOnNewline('public let operationDefinition =');
  this.withIndent(() => {
  this.multilineString(source);
  });
  @@ -163,14 +163,14 @@ export class SwiftAPIGenerator extends SwiftGenerator<CompilerContext> {
  const { operationId } = generateOperationId(operation, this.context.fragments, fragmentsReferenced);
  operation.operationId = operationId;
  this.printNewlineIfNeeded();
  - this.printOnNewline(`public static let operationIdentifier: String? = "${operationId}"`);
  + this.printOnNewline(`public let operationIdentifier: String? = "${operationId}"`);
  }
  if (fragmentsReferenced.size > 0) {
  this.printNewlineIfNeeded();
  - this.printOnNewline('public static var requestString: String { return operationString');
  + this.printOnNewline('public var queryDocument: String { return operationDefinition');
  fragmentsReferenced.forEach(fragmentName => {
  - this.print(`.appending(${this.helpers.structNameForFragmentName(fragmentName)}.fragmentString)`);
  + this.print(`.appending(${this.helpers.structNameForFragmentName(fragmentName)}.fragmentDefinition)`);
  });
  this.print(' }');
  }
  @@ -226,7 +226,7 @@ export class SwiftAPIGenerator extends SwiftGenerator<CompilerContext> {
  },
  () => {
  if (source) {
  - this.printOnNewline('public static let fragmentString =');
  + this.printOnNewline('public static let fragmentDefinition =');
  this.withIndent(() => {
  this.multilineString(source);
  });
  