PLT-3647 Email Batching (#3718)

* PLT-3647 Added config settings for email batching

* PLT-3647 Refactored generation of email notification

* PLT-3647 Added serverside code for email batching

* PLT-3647 Updated settings UI to enable email batching

* PLT-3647 Removed debug code

* PLT-3647 Fixed 0-padding of minutes in batched notification

* PLT-3647 Updated clientside UI for when email batching is disabled

* Go fmt

* PLT-3647 Changed email batching to be disabled by default

* Updated batched email message

* Added email batching toggle to system console

* Changed Email Notifications > Immediate setting to a 30 second batch interval

* Go fmt

* Fixed link to Mattermost icon in batched email notification

* Updated users to use 30 second email batching by default

* Fully disabled email batching when clustering is enabled

* Fixed email batching setting in the system console

* Fixed casing of 'Send Email notifications' -> 'Send email notifications'

* Updating UI Improvements for email batching (#3736)

* Updated text for notification settings and SiteURL.

* Prevented enabling email batching when SiteURL isn't set in the system console

* Re-added a couple debug messages

* Added warning text when clustering is enabled

webapp/components/admin_console/log_settings.jsx

@@ -204,7 +204,8 @@ export default class LogSettings extends AdminSettings {
                 >
                     <tbody>
                         <tr>
-                            <td className='help-text'>{'%T'}</td><td className='help-text'>
+                            <td>{'%T'}</td>
+                            <td>
                                 <FormattedMessage
                                     id='admin.log.formatTime'
                                     defaultMessage='Time (15:04:05 MST)'
@@ -212,7 +213,8 @@ export default class LogSettings extends AdminSettings {
                             </td>
                         </tr>
                         <tr>
-                            <td className='help-text'>{'%D'}</td><td className='help-text'>
+                            <td>{'%D'}</td>
+                            <td>
                                 <FormattedMessage
                                     id='admin.log.formatDateLong'
                                     defaultMessage='Date (2006/01/02)'
@@ -220,7 +222,8 @@ export default class LogSettings extends AdminSettings {
                             </td>
                         </tr>
                         <tr>
-                            <td className='help-text'>{'%d'}</td><td className='help-text'>
+                            <td>{'%d'}</td>
+                            <td>
                                 <FormattedMessage
                                     id='admin.log.formatDateShort'
                                     defaultMessage='Date (01/02/06)'
@@ -228,7 +231,8 @@ export default class LogSettings extends AdminSettings {
                             </td>
                         </tr>
                         <tr>
-                            <td className='help-text'>{'%L'}</td><td className='help-text'>
+                            <td>{'%L'}</td>
+                            <td>
                                 <FormattedMessage
                                     id='admin.log.formatLevel'
                                     defaultMessage='Level (DEBG, INFO, EROR)'
@@ -236,7 +240,8 @@ export default class LogSettings extends AdminSettings {
                             </td>
                         </tr>
                         <tr>
-                            <td className='help-text'>{'%S'}</td><td className='help-text'>
+                            <td>{'%S'}</td>
+                            <td>
                                 <FormattedMessage
                                     id='admin.log.formatSource'
                                     defaultMessage='Source'
@@ -244,7 +249,8 @@ export default class LogSettings extends AdminSettings {
                             </td>
                         </tr>
                         <tr>
-                            <td className='help-text'>{'%M'}</td><td className='help-text'>
+                            <td>{'%M'}</td>
+                            <td>
                                 <FormattedMessage
                                     id='admin.log.formatMessage'
                                     defaultMessage='Message'