[Swift] Adds a format file and reformats the swift project (#6250)

* Formats files & adds licence

* Revert arrays

* Keeps array indentation as is

* Adds licence to code formatter

* Updates code generators

swift.swiftformat

@@ -0,0 +1,26 @@
+--swiftversion 5.1
+
+# format
+--allman true
+--indent 2
+
+# options
+--self remove # redundantSelf
+--importgrouping testable-bottom # sortedImports
+--trimwhitespace always
+--indentcase false
+--ifdef no-indent #indent
+--wraparguments before-first # wrapArguments
+--wrapparameters before-first # wrapArguments
+--closingparen same-line # wrapArguments
+--funcattributes prev-line # wrapAttributes
+--typeattributes prev-line # wrapAttributes
+
+# rules
+--rules todos,anyObjectProtocol,redundantParens,redundantReturn,redundantSelf,sortedImports,strongifiedSelf,trailingCommas,trailingSpace,wrapArguments,wrapMultilineStatementBraces,indent,wrapAttributes,void,fileHeader
+--disable trailingclosures
+
+--exclude **/*_generated.swift
+--exclude **/*.grpc.swift
+
+--header "/*\n * Copyright {year} Google Inc. All rights reserved.\n *\n * Licensed under the Apache License, Version 2.0 (the \"License\");\n * you may not use this file except in compliance with the License.\n * You may obtain a copy of the License at\n *\n *     http://www.apache.org/licenses/LICENSE-2.0\n *\n * Unless required by applicable law or agreed to in writing, software\n * distributed under the License is distributed on an \"AS IS\" BASIS,\n * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n * See the License for the specific language governing permissions and\n * limitations under the License.\n */"