Add 'no' and 'separate' to legend interface and allow subline in legend

[tordans]

1. Add condition: no which we use in Berlin to map places where the parking:lane schema does not apply "by design" and no more specific tagging is not correct. Mainly when mapped with dual_carriageway=yes (Example), where one side is never to be parked on.

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2. Add condition: separate to give this option visibility on the legend. However (TBD), this now collides a bit with the new (and very good!) rendering of of amenity=parking. I this it's still better having it this way. What are your thoughts?

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3. This extend the legend to include an optional subline to explain the entry a bit more. ATM, its only used for one condition.

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[zlant]

May be for condition: no set description "Impossible" without subline and color #FFC7B6

[tordans]

@zlant thanks for your feedback. I rebased this and updated the code, see details in 6862315134bae918492b6ff766665eae4305c892.

You can see this version running at https://tordans.github.io/parking-lanes/#18/52.47846/13.43201

I did change a bit more than you talked about in your feedback, but the app changed as well in the meantime, so I wanted to incorporate this.

It looks like this now

[zlant]

@tordans I'm not sure if it's necessary to describe the fallback color

[tordans]

@tordans I'm not sure if it's necessary to describe the fallback color

I always prefer to have the UI explain all it's behavior in the UI itself so a new user can work on understanding what is going on. I am also quite sure that in a user test szenario without the additional text a user would have a hard time understanding why a way is marked green.

However, it's your call, so I removed it again. The most important part of this PR is to get the "no" into the legend IMO, which is solved. This is what it looks like now:

[tordans]

Let me know if I should squash manually of if you could squash on merge via the Github UI.