Added check for new extensions

[jesusgn90]

Hello team, this pull request fix an inconsistency situation whenever we add a new extension to the App which is enabled by default.

The problem comes for old App packages, whose already have .wazuh documents created without the new extension. If the new extension is enabled on the config.yml file the App thinks it is disabled.

With this pull request we are ensuring we have all the .wazuh documents with the proper extensions updated. If the document already had a extension, it is ignored, otherwise we update it adding the new extension using the default value.

To check the extensions the function reads the config.yml and compares it with default-ext.js extensions. If it's not found con config.yml, looks for it on default-ext.js. Finally looks if the current .wazuh document being analyzed has that extension, if it hasn't got it, the extension is added to its extensions with the default value, otherwise that extension is skipped for that .wazuh document.

From now and onwards we need to explicitly add any new extension to default-ext.js with its default value.

This PR fixes #455

Regards,
Jesús

[havidarou]

LGTM!