feat: dynamically find current download URL using `mongodb-platform-url`

[mindplay-dk]

Fixes #4

[mindplay-dk]

@pi0 are you still interested in maintaining this? if not, I will probably fork...

[pi0]

@mindplay-dk Feel free to fork in the meantime sorry for delays on this. I am planning to piviot mongoz idea into a new generic service runner. (also would happy to trigger a release for this, just too busy recently...)

[mindplay-dk]

@pi0 until you get around to building your new project, would you mind just merging this and triggering a release? the package is unusable as it is, and I'd prefer not to pollute npm with yet another fork of some unmaintained package. 😅