Retrieves summary of agencies matching the specified criteria.

The q parameter supports:

<ul> <li>name: search by name eg. ```name:"Agency XYZ"```</li> <li>providerId: search by providerId. eg. ```providerId:"ABC Software"```</li> <li>domainUrl: search by domainUrl. eg. ```domainUrl:"agency-xyz"```</li> <li>dateUpdated: search by dateUpdated. eg. ```dateUpdated:"2016-12-25"```</li> <li>suburbId: search by suburbId. Lists supported. eg. ```suburbId:1``` eg. ```suburbId:(1 OR 2 OR 3)```. Can include related suburbs by adding ```in:related```</li> <li>accountType: search by account type. Lists supported. eg. ```accountType:residential``` eg. ```accountType:(residential OR commercial)``` Valid values are: none, residential, commerciallight, commercialfull, developer, holiday, business</li> <li> ```in:all``` includes archived agencies (archived agencies excluded by default)</li> <li> ```-is:selfservice``` excludes selfservice</li> </ul>