implement progress bars with indicatif

[ashleygwilliams]

https://crates.io/crates/indicatif (thanks for the suggestion @killercup)

[ashleygwilliams]

zomg after https://github.com/ashleygwilliams/wasm-pack/pull/17 we def need this so bad, the experience is garbage without it (she says experiencing it rn)

[ashleygwilliams]

closed by #49