feat(directions): added possibility to toggle between two routing sources

[LAMM26]

Please check if the PR fulfills these requirements

• The commit message follows our guidelines:https://github.com/infra-geo-ouverte/igo2/blob/master/.github/CONTRIBUTING.md#git-commit-guidelines
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

What is the current behavior? (You can also link to an open issue here)
At the moment, only one routing source can be used in the Directions tool.

What is the new behavior?
Two sources can now be used. In order to see the toggle to switch between the two, you need:

To be authenticated and authorized to use the second routing source.
Two routing sources that must be provided in the configs.
When the user activates the second/private source a message warns the user.

Does this PR introduce a breaking change? (check one with "x")

[ ] Yes
[x] No

If this PR contains a breaking change, please describe the impact and migration path for existing applications:

Other information:
See infra-geo-ouverte/igo2-lib#1644