Felweed ability not consistent with original YouTD

[PiotrKaszuba]

Felweed does not scale down required hits for bonus damage throughout upgrades in its tower family. Currently:

https://github.com/Praytic/youtd2/blob/9f45418170f32cfb0e9284ea4b5a27fd96ca56cd/src/towers/tower_behaviors/felweed.gd#L4C1-L12C3

the bonuses scale only bonus damage every 2 upgrades, while originally it was supposed to reduce required hits by 1 for each bonus instance every 2 upgrades aswell.

Please, have a look at triggers attached (the whole family ids are t405-t410):
https://interactive.youtd.best/discuss/?id=t405

https://interactive.youtd.best/discuss/?id=t407

https://interactive.youtd.best/discuss/?id=t409

This results in the Felweed being worse than simple "Defender" towers' families as originally the ability factor (and thus damage->DPS) was set so that Felweed's ability had landed almost neutral with respect to its DPS. I can show the calculations if needed.