The new caching should work for reactor builds with different prefixes and injectAllReactorProjects=true

[TheSnoozer]

Context

This MR is a follow up to #414 and includes the following:

• an additional cache check for the git.build.host to avoid unnecessary calls to InetAddress.getLocalHost().getHostName() which might be costly in a multi reactor build with many modules.
• ensure caching is working correctly if we are building a reactor projects with injectAllReactorProjects=true and also specify multiple execution with a different prefix for the plugin

Essentially the following in a multi reactor build and injectAllReactorProjects=true:

<plugin>
   <groupId>pl.project13.maven</groupId>
   <artifactId>git-commit-id-plugin</artifactId>
   <version>${git-commit-id-version}</version>
   <executions>
      <execution>
         <phase>initialize</phase>
         <id>get-the-git-infos-for-repository-one</id>
         <goals>
            <goal>revision</goal>
         </goals>
         <configuration>
            <prefix>git1</prefix>
            <dotGitDirectory>${project.basedir}/../.git</dotGitDirectory>
            <generateGitPropertiesFilename>${project.build.outputDirectory}/repository_one_git.properties</generateGitPropertiesFilename>
         </configuration>
      </execution>
      <execution>
         <phase>initialize</phase>
         <id>get-the-git-infos-for-repository-two</id>
         <goals>
            <goal>revision</goal>
         </goals>
         <configuration>
            <prefix>git2</prefix>
            <dotGitDirectory>${project.basedir}/../.git</dotGitDirectory>
            <generateGitPropertiesFilename>${project.build.outputDirectory}/repository_two_git.properties</generateGitPropertiesFilename>
         </configuration>
      </execution>
   </executions>
   <configuration>
      <prefix>git</prefix>
      <verbose>true</verbose>
      <skipPoms>false</skipPoms>
      <dotGitDirectory>${project.basedir}/../.git</dotGitDirectory>
      <injectAllReactorProjects>true</injectAllReactorProjects>
      <generateGitPropertiesFile>true</generateGitPropertiesFile>
      <evaluateOnCommit>HEAD</evaluateOnCommit>
      <generateGitPropertiesFilename>${project.build.outputDirectory}/git.properties</generateGitPropertiesFilename>
   </configuration>
</plugin>

Contributor Checklist

• Added relevant integration or unit tests to verify the changes
• Update the Readme or any other documentation (including relevant Javadoc)
• Ensured that tests pass locally: mvn clean package
• Ensured that the code meets the current checkstyle coding style definition: mvn clean verify -Pcheckstyle -Dmaven.test.skip=true -B