[ticket/11713] Do not remove module if it couldn't be deleted

Up to now, the module or module category was always removed with jQuery,
even if there was an error. With this change, the modules will not be deleted
by jQuery if the return JSON array will have SUCCESS set to false.

PHPBB3-11713
Merge pull request #1584 from marc1706/ticket/11713

[ticket/11713] Do not remove module if it couldn't be deleted
[ticket/11720] Do not call $captcha->validate if $captcha is not set

PHPBB3-11566 changed big parts of code. Unfortunately, a call to
$captcha->validate was added that is being called even if $captcha hasn't
been initialized. This change will fix this issue.

PHPBB3-11720
[ticket/11720] Add functional test for submitting report as user

The already existing functional tests were not ran as the filename was
missing the appended "_test".

PHPBB3-11720
Merge remote-tracking branch 'marc1706/ticket/11720-prep-release' into prep-release-3.0.12

* marc1706/ticket/11720-prep-release:
  [ticket/11720] Add functional test for submitting report as user
  [ticket/11720] Do not call $captcha->validate if $captcha is not set
Merge branch 'prep-release-3.0.12' into develop-olympus

* prep-release-3.0.12:
  [ticket/11720] Add functional test for submitting report as user
  [ticket/11720] Do not call $captcha->validate if $captcha is not set
Merge branch 'develop-olympus' into develop

* develop-olympus:
  [ticket/11720] Add functional test for submitting report as user
  [ticket/11720] Do not call $captcha->validate if $captcha is not set