feat: query string dynamic app config (#3391)

* feat: query string dynamic app config

* fix: bug fix and couple of very small improvements

platform/viewer/public/config/default.js

@@ -25,6 +25,16 @@ window.config = {
   },
   // filterQueryParam: false,
   defaultDataSourceName: 'dicomweb',
+  /* Dynamic config allows user to pass "configUrl" query string this allows to load config without recompiling application. The regex will ensure valid configuration source */
+  // dangerouslyUseDynamicConfig: {
+  //   enabled: true,
+  //   // regex will ensure valid configuration source and default is /.*/ which matches any character. To use this, setup your own regex to choose a specific source of configuration only.
+  //   // Example 1, to allow numbers and letters in an absolute or sub-path only.
+  //   // regex: /(0-9A-Za-z.]+)(\/[0-9A-Za-z.]+)*/
+  //   // Example 2, to restricts to either hosptial.com or othersite.com.
+  //   // regex: /(https:\/\/hospital.com(\/[0-9A-Za-z.]+)*)|(https:\/\/othersite.com(\/[0-9A-Za-z.]+)*)/
+  //   regex: /.*/,
+  // },
   dataSources: [
     {
       friendlyName: 'dcmjs DICOMWeb Server',