Antoine Stevan f9cf1d943c
standard library: use the standard assert and fix test output (#8509)
# Description
## in the `test_dirs` test module
- use the `std assert` function in the `test_dirs` module instead of
`myassert`
- refactor the "test cleaning" in the `clean` command
- allows to clean the tests and then throw a real error in the `catch`
block in case there is an error
- the test still "try"s to `clean` the test directory after the `catch`,
like in a "finally" block
- parse the `catch` error and `error make` a proper one instead of
`debug`ging it => because the `catch` will be triggered as soon as one
error occurs, there will always only be a single error in the tests, so
this does not change the behaviour of failing `dirs` tests!

> **Note**
> i'm not particularly happy with the parsing stage in the `catch`
block.
> however that's the simplest i found to both keep the `try` / `catch`
construct that allows to clean the test directory and have a proper
error at the same time!

## in the global `tests` module
- use `print` instead of `echo` to make sure the log statements show up
during the tests

# User-Facing Changes
```
$nothing
```

# Tests + Formatting
```bash
nu crates/nu-utils/standard_library/tests.nu
```
passes but now with
- proper log statements
- proper error when a `dirs` error occurs => try with `sd 'assert \(1'
"assert (10" crates/nu-utils/standard_library/test_dirs.nu` 😉

# After Submitting
```
$nothing
```
2023-03-18 09:23:41 -05:00
..
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2023-03-17 21:29:15 +13:00