Check group variable type to avoid fatal error with iTop provider

Description

Closes https://github.com/centreon/centreon-open-tickets/pull/237/files

Fix fatal error in centreon-error.log when trying to open a ticket with iTop provider.

Uncaught TypeError: count(): Argument #1 ($value) must be of type Countable|array, string given in /usr/share/centreon/GPL_LIB/SmartyCache/compile/fdf91122f2894e9f67b971588eee542ebcb59e37_0.file.group.ihtml.php:41

The reason is that the iTop provider have dynamic lists that are displayed. The $group variable for those lists will only be set when other lists have a selected value.

The issue happens since https://github.com/centreon/centreon-open-tickets/commit/5f17e24afa4690ef43132dc90b947b58ebb0a795 so it is better to handle it right from the smarty file

Type of change

[x] Patch fixing an issue (non-breaking change)
[ ] New functionality (non-breaking change)
[ ] Breaking change (patch or feature) that might cause side effects breaking part of the Software

Target serie

[ ] 21.04.x
[ ] 21.10.x
[ ] 22.04.x
[x] 22.10.x (master)

How this pull request can be tested ?

without the patch
- use the itop provider
- try to open a ticket
- the popup will never work and you'll have a fatal error in your centreon-error.log
with the patch
- the popup will work fine
- try to open a ticket with an other provider to confirm there isn't any side-effect

Checklist

Community contributors & Centreon team

[ ] I have followed the coding style guidelines provided by Centreon
[ ] I have commented my code, especially new classes, functions or any legacy code modified. (docblock)
[ ] I have commented my code, especially hard-to-understand areas of the PR.
[ ] I have rebased my development branch on the base branch (master, maintenance).

centreon / centreon-open-tickets

Check group variable type to avoid fatal error with iTop provider #242