Reorganize system alert messages based on bootstrap alerts

[alvinBM]

No description provided.

[alvinBM]

Hello @josaphatim , This PL is ready

[josaphatim]

In my opinion, the Hm_Notices::show function to which we pass an array of messages as the first parameter should display an alert for each message instead of having a single alert for all the messages passed separated by a comma.
But also in the same function please add the type of error depending on ERR passed before the string or not.

But also the Hm_Utils::show_sys_messages method had the sole responsibility of displaying pending messages already added to the element $('.sys_messages') via elements having the .err class.

I think it could keep the same role but just think about how to keep messages waiting before displaying

[alvinBM]

Hm_Notices ins't showing any alert #919

Fixed @josaphatim, Thanks