CustomCacheKeyGenerator key generator not hashing class or method names or params

The compilation of CustomCacheKeyGenerator.groovy [CacheKey.hashCode()](https://github.com/grails-plugins/grails-cache/blob/c442583e552e03d297ee1aa144daf716a80c509f/src/ast/groovy/grails/plugin/cache/CustomCacheKeyGenerator.groovy#L56-L69) and [TemporaryGrailsCacheKey.hashCode()](https://github.com/grails-plugins/grails-cache/blob/c442583e552e03d297ee1aa144daf716a80c509f/src/ast/groovy/grails/plugin/cache/CustomCacheKeyGenerator.groovy#L141-L154) implementation into bytecode ignores the `targetClassName`, `targetMethodName` & `simpleKey`

decompiled bytecode:
```
public int hashCode() {
int prime = 31;
int result = 1;
int var3 = prime * result;
boolean var10000;
if (this.simpleKey == null) {
var10000 = false;
} else {
this.simpleKey.hashCode();
}

int var4 = prime * var3;
if (this.targetClassName == null) {
var10000 = false;
} else {
this.targetClassName.hashCode();
}

int var5 = prime * var4;
if (this.targetMethodName == null) {
var10000 = false;
} else {
this.targetMethodName.hashCode();
}

int var6 = prime * var5 + this.targetObjectHashCode;
return var6;
}
```

Start in src/ast/groovy/grails/plugin/cache/CustomCacheKeyGenerator.groovy at CacheKey.hashCode() and TemporaryGrailsCacheKey.hashCode(), then compare the Groovy source with the decompiled bytecode shown in the issue. Done means the compiled hashCode implementations account for targetClassName, targetMethodName, and simpleKey rather than discarding their hash values.

Written by the indexing model from the issue text.