dataexport supplements

[mszell]

• @mszell gbn: missing seed point variations
• @Manuel-Knepper fbn: once it works (tested on Copenhagen Swap range limitation and node sampling for local btw calc FixBikeNet#33): 1) top 100 gaps, 2) replace b with benefit, 3) also export existing bicycle network, 4) also Copenhagen
• @mszell sb: Provide which info to show in tooltip, which values to sum or avg over blocks