Update to Laravel 5.7 (PHP 7.3 support) (#9800)

* Move assets to 5.7 location

* Add 5.7 SVGs

* add cache data dir

* update QUEUE_DRIVER -> QUEUE_CONNECTION

* Update trusted proxy config

* update composer.json

* 5.5 command loading

* @php and @endphp can't be inline

* Laravel 5.6 logging, Nice!

* Update blade directives

* improved redirects

* remove unneeded service providers

* Improved debugbar loading

* no need to emulate renderable exceptions anymore

* merge updated 5.7 files (WIP)

* Enable CSRF

* database_path() call causes issue in init.php

* fix old testcase name

* generic phpunit 7 fixes

* add missed file_get_contents
Keep migrations table content

* fix duplicate key

* Drop old php versions from travis-ci

* remove hhvm

* fix code climate message

* remove use of deprecated function assertInternalType

* Disable CSRF, we'll enable it separately.
All forms need to be updated to work.

* Update document references

phpunit.xml

@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<phpunit
+<phpunit backupGlobals="true"
+         backupStaticAttributes="false"
          bootstrap="tests/bootstrap.php"
          colors="true"
          convertErrorsToExceptions="true"
@@ -32,8 +33,10 @@
     </filter>
     <php>
         <env name="APP_ENV" value="testing"/>
+        <env name="BCRYPT_ROUNDS" value="4"/>
         <env name="CACHE_DRIVER" value="array"/>
+        <env name="MAIL_DRIVER" value="array"/>
+        <env name="QUEUE_CONNECTION" value="sync"/>
         <env name="SESSION_DRIVER" value="array"/>
-        <env name="QUEUE_DRIVER" value="sync"/>
     </php>
 </phpunit>