chore: bump rand(_core, _chacha) to 0.10

[wuvs]

0.10 changelog:

• Rename Rng -> RngExt
• Rename fn IndexedRandom::choose_multiple -> sample
• The dependency on rand_chacha has been replaced with a dependency on chacha20. This changes the implementation behind StdRng, but the output remains the same. There may be some API breakage when using the ChaCha-types directly as these are now the ones in chacha20 instead of rand_chacha

[cksac]

why need RngExt? I would prefer to keep Rng instead

[wuvs]

because rand and rand_core renamed Rnd

rust-random/rand#1717

[francisdb]

@cksac any chance this could get released? It's blocking the rand update on our project.

[cksac]

@francisdb released v5.0.0

[francisdb]

There's a regression relate to this: #270