Bump crate versions to 4.0

[HCastano]

While working on use-ink/cargo-contract#641 I realized that
ink!'s master branch was still based on 3.2. This makes for a strange situation in
which we're "downgrading" from ink! 3.3 to 3.2 in order to work off master.

I figured since the master branch already includes breaking changes it would be
appropriate to bump all the version numbers anyways.

[paritytech-cicd-pr]

🦑 📈 ink! Example Contracts ‒ Changes Report 📉 🦑

These are the results when building the examples/* contracts from this branch with cargo-contract 1.4.0-25bfb96 and comparing them to ink! master:

	Δ Optimized Size	Δ Used Gas	Total Optimized Size	Total Used Gas
accumulator			1.00 K
adder			2.04 K
contract-introspection			2.32 K
contract-terminate			0.92 K	275_000
contract-transfer			8.31 K	75_000
data-structures			1.73 K
delegate-calls			2.89 K	76_242
delegator		-1	6.34 K	232_135
dns			8.81 K	225_000
erc1155			16.74 K	450_000
erc20			8.42 K	225_000
erc721			11.62 K	600_000
flipper			1.24 K	75_000
forward-calls			2.87 K	151_411
incrementer			1.14 K
mother			12.16 K
multisig			25.28 K	470_240
rand-extension			3.79 K	75_000
seal-code-hash			1.39 K
seal-ecdsa			1.71 K
set-code-hash			1.49 K	150_000
subber			2.06 K
trait-erc20			8.69 K	225_000
trait-flipper			0.97 K	75_000
trait-incrementer			1.12 K	150_000
updated-incrementer			9.72 K
upgradeable-flipper			1.48 K

Link to the run | Last update: Mon Jul 11 23:15:17 CEST 2022

[cmichi]

I figured since the master branch already includes breaking changes it would be appropriate to bump all the version numbers anyways.

Are those also changes to the examples?

Generally we had bad experience in the past with making the examples contain changes incompatible with our published crates. People rightfully assume that they can copy/paste example code and if that code is not working out of the box it's a bad onboarding experience.

[HCastano]

Are those also changes to the examples?

Generally we had bad experience in the past with making the examples contain changes incompatible with our published crates. People rightfully assume that they can copy/paste example code and if that code is not working out of the box it's a bad onboarding experience.

At the moment no, it's fine to copy-paste the examples and build them with 3.x dependencies. This is part of the reason why we were able to release backwards incompatible changes after 3.0.1 and not realize, haha.

However, after Green's storage changes this will not be the case.

At that point if people want working 3.x examples they will need to grab them from the 3.x branch instead of master.