Correct IPA 005 rule file name (#683)

Author: lovisaberggren

tools/spectral/ipa/__tests__/IPA105exceptionExtensionFormat.test.js renamed to tools/spectral/ipa/__tests__/IPA005ExceptionExtensionFormat.test.js

@@ -2,7 +2,7 @@
 # http://go/ipa/5
 
 functions:
-  - IPA105ExceptionExtensionFormat
+  - IPA005ExceptionExtensionFormat
 
 rules:
   xgen-IPA-005-exception-extension-format:
@@ -18,4 +18,4 @@ rules:
     severity: error
     given: '$..x-xgen-IPA-exception'
     then:
-      function: 'IPA105ExceptionExtensionFormat'
+      function: 'IPA005ExceptionExtensionFormat'