Fixed: Convert PeriodServices.xml mini lang to groovy (OFBIZ-12962)

We have a Gradle redundant classes clash

Because there is already a PeriodServices Java class and we compile also Groovy
we can't create a PeriodServices.groovy class as pointed by GH actions, and
clearly by BB
https://ci2.apache.org/#/builders/49/builds/826/steps/2/logs/stdio
Caused by: org.gradle.api.InvalidUserCodeException:
Entry org/apache/ofbiz/accounting/period/PeriodServices.class
is a duplicate but no duplicate handling strategy has been set.

This is a workaround. We can use a better name for GPeriodServices.groovy
And maybe use a duplicate handling strategy (complicated?)

applications/accounting/servicedef/services_ledger.xml

@@ -536,7 +536,7 @@ under the License.
 
  <!-- CustomTimePeriod Services -->
  <service name="findCustomTimePeriods" engine="groovy" invoke="findCustomTimePeriods" auth="true"
- location="component://accounting/src/main/groovy/org/apache/ofbiz/accounting/period/PeriodServices.groovy">
+ location="component://accounting/src/main/groovy/org/apache/ofbiz/accounting/period/GPeriodServices.groovy">
  <description>Find CustomTimePeriod records, returns both general ones and those for the organizationPartyId passed</description>
  <attribute name="findDate" type="Timestamp" mode="IN"/>
  <attribute name="organizationPartyId" type="String" mode="IN" optional="true"/>
@@ -558,7 +558,7 @@ under the License.
  <attribute name="lastClosedTimePeriod" type="org.apache.ofbiz.entity.GenericValue" mode="OUT" optional="true"/>
  </service>
  <service name="getPreviousTimePeriod" engine="groovy" invoke="getPreviousTimePeriod" auth="true"
- location="component://accounting/src/main/groovy/org/apache/ofbiz/accounting/period/PeriodServices.groovy">
+ location="component://accounting/src/main/groovy/org/apache/ofbiz/accounting/period/GPeriodServices.groovy">
  <description>Return previous year with respect to the given year and if none found then return null.</description>
  <attribute name="customTimePeriodId" mode="IN" type="String"/>
  <attribute name="previousTimePeriod" mode="OUT" type="Map" optional="true"/>