Group results of runs by feature file instead of teams

# Group results of runs by feature file instead of teams

## Context

For now, runs are grouped by teams:

Small projects only have one team, so this grouping is irrelevant to them.

Such teams would prefer to sort by Cucumber feature file and Postman collection file, like any other report tools:

## Expected
Add a new setting for the project: "Group run results by".

This should be a drop-down-list with these three values:

* Automatic (the default value: by team if project have at least one team, and by file otherwise)
* Team (explicitly set to team-grouping, no matter what "Automatic" would decide)
* File (explicitly set to file-grouping, no matter what "Automatic" would decide)
These progress-bars are both in ARA and in emails.

Be careful: these progress-bars are clickable: they need to link to the correct filters depending on the setting effective value.