Add bot.entityInSight() (recreation of #1371)

[au5ton]

This is a re-opening of https://github.com/PrismarineJS/mineflayer/pull/1371 after making the changes requested in: https://github.com/PrismarineJS/mineflayer/pull/1371#issuecomment-712040319

I would've used the original pull request, but the author's GitHub account was deleted, so I wasn't sure how to go about doing that.

This worked well for me in my limited testing.

[extremeheat]

Dupe of https://github.com/PrismarineJS/mineflayer/pull/2077 ?

[extremeheat]

This implementation seems cleaner with a width feature though. Making the name match the current block methods sounds like a good idea, like entityAtCursor() in the other PR

[au5ton]

This implementation seems cleaner with a width feature though. Making the name match the current block methods sounds like a good idea, like entityAtCursor() in the other PR

Are there any changes you'd like me to make, maybe specifically with the naming? I tried to follow the convention I saw in the other methods.

After looking at the other PR (#2077 ) it looks like I forgot to update the API docs, too.

[u9g]

If you can make a test too, that would be great.

[extremeheat]

This does not seem to test for obstructions. entityInSight() may return something even if a wall is in front of the bot.

[rom1504]

add test or example

[rom1504]

please re-open if you want to finish it