Sign a bundle with symlinks and verify symlink overwrites work

```
$ rcodesign debug-create-macho MyApp.app/Contents/MacOS/MyApp
assuming default minimum version 11.0.0
writing Mach-O to MyApp.app/Contents/MacOS/MyApp

$ rcodesign debug-create-info-plist --bundle-name MyApp MyApp.app/Contents/Info.plist
writing MyApp.app/Contents/Info.plist

$ mkdir -p MyApp.app/Contents/Resources
$ touch MyApp.app/Contents/Resources/file-00.txt
$ touch MyApp.app/Contents/Resources/file-01.txt
$ ln -s file-00.txt MyApp.app/Contents/Resources/file.txt

$ rcodesign sign MyApp.app MyApp.app.signed
signing MyApp.app to MyApp.app.signed
signing bundle at MyApp.app
signing bundle at MyApp.app into MyApp.app.signed
signing main executable Contents/MacOS/MyApp

$ ln -sf file-01.txt MyApp.app/Contents/Resources/file.txt

$ rcodesign sign MyApp.app MyApp.app.signed
signing MyApp.app to MyApp.app.signed
signing bundle at MyApp.app
signing bundle at MyApp.app into MyApp.app.signed
signing main executable Contents/MacOS/MyApp

$ rcodesign debug-file-tree MyApp.app.signed
d                      MyApp.app.signed/
d                      MyApp.app.signed/Contents
f 0a5902dc8e47f490d038 MyApp.app.signed/Contents/Info.plist
d                      MyApp.app.signed/Contents/MacOS
f 92cc3ed9973cf49d2574 MyApp.app.signed/Contents/MacOS/MyApp
d                      MyApp.app.signed/Contents/Resources
f e3b0c44298fc1c149afb MyApp.app.signed/Contents/Resources/file-00.txt
f e3b0c44298fc1c149afb MyApp.app.signed/Contents/Resources/file-01.txt
l                      MyApp.app.signed/Contents/Resources/file.txt -> file-01.txt
d                      MyApp.app.signed/Contents/_CodeSignature
f bafb4e22a57de8763dc1 MyApp.app.signed/Contents/_CodeSignature/CodeResources

```