ink! 3.0-rc3 pre-release changes and adjustments (#713)

* adjust rustfmt.toml

* add ink-fizz-tests feature guard to some test API

* update ink! crates to version 3.0.0-rc3

* write release notes for ink! 3.0-rc3

* apply formatting to imports_granularity
16 jobs for v3.0.0-rc3 in 10 minutes and 13 seconds (queued for 2 seconds)
latest
Status Job ID Name Coverage
  Check
passed #833819
linux-docker
check-std

00:02:11

passed #833820
linux-docker
check-wasm

00:01:52

 
  Workspace
passed #833821
linux-docker
build-std

00:02:20

passed #833822
linux-docker
build-wasm

00:02:02

passed #833826
linux-docker
clippy-std

00:02:02

passed #833827
linux-docker
clippy-wasm

00:01:47

passed #833825
linux-docker
codecov

00:04:21

passed #833824
linux-docker
docs

00:01:03

passed #833828
linux-docker
fmt

00:00:56

passed #833823
linux-docker
test

00:02:54

 
  Examples
passed #833831
linux-docker
examples-clippy-std

00:01:25

passed #833832
linux-docker
examples-clippy-wasm

00:01:13

passed #833833
linux-docker
examples-contract-build

00:03:34

passed #833834
linux-docker
examples-docs

00:01:22

passed #833830
linux-docker
examples-fmt

00:00:15

passed #833829
linux-docker
examples-test

00:01:37