Refactor mongo macros in filters

[lunika]

Feature Request

Is your feature request related to a problem or unsupported use case? Please describe.

To manage mongo connection we created macros responsible to create the good connection depending on many parameters. This is not ideal and a filter is better to do this job

Describe the solution you'd like

create at least 2 filters: One to create a list of mongo hosts and an other other to create a valid mongodb URI. The second filter will the use the first one.

[jmaupetit]

FTR this is a postponed work from #396