eslint:analyze suppressed based on theme exemptions for eslint:validate

[grayside]

eslint:validate and eslint:analyze can target different files per the theme exemption provided by configuring Gruntconfig.json with the respective script, but only the validate tasks files mask is checked to determine if eslint should be configured at all for Grunt Drupal Tasks.

Instead, if either mask is successful eslint should be configured for the appropriate operation.

For bonus points, larger codebases will find the extra run of the file expansion to be moderately costly in performance, but the analyze task is not automatically triggered by the build like validate. As such, we can adjust how we define analyze to only run the file match if the grunt analyze task was run. This will minimize the impact of the analyze processing on other grunt jobs, including the main build process and grunt help.

[grayside]

This was uncovered as part of the work done in #214