Handle membership exceptions for synchronized root groups

[mirkokg]

Adds logic to detect and register membership exceptions for PBXFileSystemSynchronizedRootGroup objects, specifically excluding Info.plist files from group membership when necessary. Also ensures resources build phase is added if synchronized root groups are present.

I noticed that current implementation of synchronizedGroups does not ignore Info.plist.
I inspected default Xcode behavior and noticed that when you create new Xcode project you get empty copy Resources section:

/* Begin PBXResourcesBuildPhase section */
		232C80EF2ECFA3E300DF1D84 /* Resources */ = {
			isa = PBXResourcesBuildPhase;
			buildActionMask = 2147483647;
			files = (
			);
			runOnlyForDeploymentPostprocessing = 0;
		};
/* End PBXResourcesBuildPhase section */

If this empty PBXResourcesBuildPhase is not present xcassets will not be copied automatically for syncedFolder.

I also noticed that by default it adds Info.plist to ignore list as PBXFileSystemSynchronizedBuildFileExceptionSet:

/* Begin PBXFileSystemSynchronizedBuildFileExceptionSet section */
		232C81032ECFA3E400DF1D84 /* Exceptions for "tester" folder in "tester" target */ = {
			isa = PBXFileSystemSynchronizedBuildFileExceptionSet;
			membershipExceptions = (
				Info.plist,
			);
			target = 232C80F02ECFA3E300DF1D84 /* tester */;
		};
/* End PBXFileSystemSynchronizedBuildFileExceptionSet section */

There are three functionalities implemented with this patch:

• Allows you to add excludes for syncedFolder
• Adds exclude for Info.plist if its within the syncedFolder
• Adds empty copy resources build phase for resources to be copied

This patch fixes an issue with synchronized folders reported by @KieranHarper :

#1586

[mirkokg]

I also created a PR to fix TEMP_ prefixes for PBXFileSystemSynchronizedBuildFileExceptionSet tuist/XcodeProj#1014 in Xcodeproj, but besides cosmetic problem this issue does not affect XcodeGen negatively.

[mirkokg]

@yonaskolb please review and let me know if you would change anything. I tested with my projects and all worked perfectly with my version.