patching: do strict version range checking (#13989)

* apply strict constraint checks for patches, otherwise Spack may incorrectly treat a version range constraint as satisfied when mixing x.y and x.y.z versions
* add mixed version checks to version comparison tests

var/spack/repos/builtin.mock/packages/patch/biz.patch

@@ -0,0 +1 @@
+this patch is never applied, it is used to check spec semantics on when the concretizer chooses to include a patch

var/spack/repos/builtin.mock/packages/patch/package.py

@@ -13,11 +13,14 @@ class Patch(Package):
     url = "http://www.example.com/patch-1.0.tar.gz"
 
     version('1.0', '0123456789abcdef0123456789abcdef')
+    version('1.0.1')
+    version('1.0.2')
     version('2.0', '0123456789abcdef0123456789abcdef')
 
     patch('foo.patch')
     patch('bar.patch', when='@2:')
     patch('baz.patch')
+    patch('biz.patch', when='@1.0.1:1.0.2')
 
     def install(self, spec, prefix):
         pass