Full project restructure about flood-map

[planemad]

@prasannavl thank you for doing this! The rains are back and I just reset the data for new reports.

Are your changes still relevant?

[prasannavl]

I don't see why not. However, two things I'd take into account:

1. My branch is still a little old, since I see a few commits from last year here that wouldn't be there.
   Merging them may be as easy as it's just works, or might require a bit of manual work.
2. Once 1 is done, everything including node, npm, and the deps have to be brought up to date.

If you could do 1, I should be able to make some time towards the end of the week.