Update codegen after SCALE v3.1.2 release

[HCastano]

So it looks like a feature introduced in parity-scale-codec v3.1 accidently removed
some old functionality. The v3.1.2 release brings this back (paritytech/parity-scale-codec#328).

This PR basically reverts #1180.

[cmichi]

Can you create another PR for a patch release of this crate?

[paritytech-cicd-pr]

🦑 📈 ink! Example Contracts ‒ Changes Report 📉 🦑

These are the results when building the examples/* contracts from this branch with cargo-contract 0.18.0-9362c04 and comparing them to ink! master:

	Δ Optimized Size	Δ Used Gas	Total Optimized Size	Total Used Gas
accumulator			1.03 K
adder			2.17 K
contract-introspection			2.37 K
contract-terminate			0.94 K	214_418
contract-transfer			8.15 K	14_418
delegator			6.37 K	46_295
dns			8.84 K	43_254
erc1155			17.23 K	86_508
erc20			8.49 K	43_254
erc721			11.81 K	115_344
flipper			1.31 K	14_418
incrementer			1.21 K	14_418
multisig			25.20 K	93_527
proxy			2.90 K	29_536
rand-extension			3.92 K	14_418
subber			2.19 K
trait-erc20			8.76 K	43_254
trait-flipper			1.00 K	14_418
trait-incrementer			1.19 K	28_836
upgradeable-contract			2.99 K	14_950
upgradeable-flipper			1.55 K

Link to the run | Last update: Thu Mar 17 17:47:34 CET 2022

[codecov-commenter]

Codecov Report

Merging #1189 (a70b896) into master (a35e159) will decrease coverage by 4.48%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #1189      +/-   ##
==========================================
- Coverage   78.98%   74.50%   -4.49%     
==========================================
  Files         229      228       -1     
  Lines        8667     8637      -30     
==========================================
- Hits         6846     6435     -411     
- Misses       1821     2202     +381     

Impacted Files	Coverage Δ
...odegen/src/generator/as_dependency/call_builder.rs	100.00% <ø> (ø)
...odegen/src/generator/as_dependency/contract_ref.rs	100.00% <ø> (ø)
crates/lang/codegen/src/generator/events.rs	97.26% <ø> (ø)
...ng/codegen/src/generator/trait_def/call_builder.rs	100.00% <ø> (ø)
.../codegen/src/generator/trait_def/call_forwarder.rs	100.00% <ø> (ø)
crates/lang/ir/src/ir/contract.rs	0.00% <0.00%> (-100.00%)	⬇️
crates/lang/ir/src/ir/ink_test.rs	0.00% <0.00%> (-87.50%)	⬇️
crates/lang/ir/src/ir/trait_def/mod.rs	0.00% <0.00%> (-83.34%)	⬇️
crates/eth_compatibility/src/lib.rs	0.00% <0.00%> (-74.08%)	⬇️
crates/lang/ir/src/ir/blake2.rs	20.00% <0.00%> (-60.00%)	⬇️
... and 33 more

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