Assets: Remove zombies, introduce approvals (#8220)

* Initial work

* Tests for frame system

* Self-sufficient account ref-counting

* Fixes

* Benchmarks building.

* Update frame/system/src/lib.rs

Co-authored-by: Jaco Greeff <jacogr@gmail.com>

* Fixes

* Fixes

* Fixes

* Fixes

* Fixes

* Fixes

* Test approvals

* Fixes

* Report assets pallet tests

* Tests for approvals & force_cancel_approval

* Use structs rather than tuples for approval data

* Add force_asset_status, force_set_metadata

* Add clear_metadata.

* approval benchmarks

* force_asset_status benchmarks

* final benchmarks

* cargo run --release --features=runtime-benchmarks --manifest-path=bin/node/cli/Cargo.toml -- benchmark --chain=dev --steps=50 --repeat=20 --pallet=pallet_assets --extrinsic=* --execution=wasm --wasm-execution=compiled --heap-pages=4096 --output=./frame/assets/src/weights.rs --template=./.maintain/frame-weight-template.hbs

* Update frame/system/src/lib.rs

Co-authored-by: Guillaume Thiolliere <gui.thiolliere@gmail.com>

* Update frame/system/src/lib.rs

Co-authored-by: Guillaume Thiolliere <gui.thiolliere@gmail.com>

* Update frame/system/src/lib.rs

Co-authored-by: Guillaume Thiolliere <gui.thiolliere@gmail.com>

* Docs for new approval dispatches.

* Docs for pallet.

* Remove accidental code.

* cargo run --release --features=runtime-benchmarks --manifest-path=bin/node/cli/Cargo.toml -- benchmark --chain=dev --steps=50 --repeat=20 --pallet=pallet_assets --extrinsic=* --execution=wasm --wasm-execution=compiled --heap-pages=4096 --output=./frame/assets/src/weights.rs --template=./.maintain/frame-weight-template.hbs

* cargo run --release --features=runtime-benchmarks --manifest-path=bin/node/cli/Cargo.toml -- benchmark --chain=dev --steps=50 --repeat=20 --pallet=pallet_assets --extrinsic=* --execution=wasm --wasm-execution=compiled --heap-pages=4096 --output=./frame/assets/src/weights.rs --template=./.maintain/frame-weight-template.hbs

* Fixes

* Update frame/assets/src/lib.rs

Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>

* Grumbles.

* Transfer zero works, use DispatchResult

* fix test

* Remove force_destroy

* Remove TODO

* cargo run --release --features=runtime-benchmarks --manifest-path=bin/node/cli/Cargo.toml -- benchmark --chain=dev --steps=50 --repeat=20 --pallet=pallet_assets --extrinsic=* --execution=wasm --wasm-execution=compiled --heap-pages=4096 --output=./frame/assets/src/weights.rs --template=./.maintain/frame-weight-template.hbs

* transfer_keep_alive

* Fixes

* Fixes

* Fixes

* cargo run --release --features=runtime-benchmarks --manifest-path=bin/node/cli/Cargo.toml -- benchmark --chain=dev --steps=50 --repeat=20 --pallet=pallet_assets --extrinsic=* --execution=wasm --wasm-execution=compiled --heap-pages=4096 --output=./frame/assets/src/weights.rs --template=./.maintain/frame-weight-template.hbs

Co-authored-by: Jaco Greeff <jacogr@gmail.com>
Co-authored-by: Parity Benchmarking Bot <admin@parity.io>
Co-authored-by: Guillaume Thiolliere <gui.thiolliere@gmail.com>
Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>