Remove nervosnetwork/faketime, replace cargo test by nextest-rs/nextest

[eval-exec]

What problem does this PR solve?

Issue Number: close #3729

Problem Summary:

This PR want to remove nervosnetwork/faketime, and simply use static atomics and nextest to organize ckb's unit tests.

What is changed and how it works?

The nervosnetwork/faketime is complicated, and when we specified --test-threads=1 flag to cargo test, these thread_local (
https://github.com/nervosnetwork/faketime/blob/1ead0aba139f0893d04aa95c35e0179c3b4482c7/src/faketime.rs#L109-L115 ) behave like global variables, then some tests will fail.

The cargo test run all unit test in a single process, and many unit tests may run on a same thread. And there exists some faketime related test want to change the whole process's faketime by set current process's environment like this:

ckb/chain/src/tests/block_assembler.rs

Line 135 in fafa37d

::std::env::set_var("FAKETIME", faketime_file.as_os_str());

this may affect other non-faketime related unit tests.

Fortunately, there is nextest-rs/nextest which will run every unit function on single process, providing process-level isolation granularity.

What's Changed:

Related changes

• remove nervosnetwork/faketime
• add util/systemtime to provide real systemtime, and provide faketime when enable_faketime feature is enabled
• use nextest-rs/nextest to run all unit tests

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No code ci-runs-only: [ quick_checks,linters ]

Side effects

• None

Release note

Title Only: Include only the PR title in the release note.

[eval-exec]

Try to make github ci action use cargo-nextest.
But get an error on Windows platform:
https://github.com/nervosnetwork/ckb/actions/runs/3799433532/jobs/6461954529

error: failed to compile `cargo-nextest v0.9.47`, intermediate artifacts can be found at `C:\Users\ADMINI~1\AppData\Local\Temp\cargo-installaoztQa`

Caused by:
  package `cargo-nextest v0.9.47` cannot be built because it requires rustc 1.62 or newer, while the currently active rustc version is 1.61.0
Error: Process completed with exit code 1.

Trying to install an older version of cargo-nextest on ci_*_windows

[zhangsoledad]

bors r+

[bors]

Build succeeded:

• ci_benchmarks_ubuntu
• ci_cargo_deny_ubuntu
• ci_integration_tests_ubuntu
• ci_linters_ubuntu
• ci_quick_checks_ubuntu
• ci_unit_tests_ubuntu
• ci_wasm_build_ubuntu