New: Add application URL to host configuration settings

Fixes #1816
Closes #1817

(cherry picked from commit 762042ba97c2ae689cee32d8e66a458f6d7a8adc)

frontend/src/Settings/General/HostSettings.js

@@ -21,6 +21,7 @@ function HostSettings(props) {
     port,
     urlBase,
     instanceName,
+    applicationUrl,
     enableSsl,
     sslPort,
     sslCertPath,
@@ -96,6 +97,21 @@ function HostSettings(props) {
         />
       </FormGroup>
 
+      <FormGroup
+        advancedSettings={advancedSettings}
+        isAdvanced={true}
+      >
+        <FormLabel>{translate('ApplicationURL')}</FormLabel>
+
+        <FormInputGroup
+          type={inputTypes.TEXT}
+          name="applicationUrl"
+          helpText={translate('ApplicationUrlHelpText')}
+          onChange={onInputChange}
+          {...applicationUrl}
+        />
+      </FormGroup>
+
       <FormGroup
         advancedSettings={advancedSettings}
         isAdvanced={true}