* Add `date format --list`, and make format string optional (providing default)
* Make DRY
`into datetime --list` now uses `generate_strfttime_list` from `date format --list`
* refactor strftime to use current datetime
* Fix formatting of specification descriptions
Fixes issues caused when copying directly from docs.rs
* Change default format to rfc2822
Perhaps to make it more DRY, functions from `into datetime` can be used. However, currently `into datetime` is a bit tricky to use as it needs a separate time zone argument.
* Tweak in-shell docs to match modified behavior
* Show %#z format specifier in `into datetime --list` only
* cargo fmt
* Satisfy clippy
* Add different features combinations
* Specify styles manually
* Fix args
* Fix typo
* Let other CI jobs finish if one fails
* Fix unused symbols without plugin feature
* Put "which" tests behind "which" feature
* Add Python virtualenv job
* Oops forgot git command
* Install Nushell in virtualenv tests
* Add names to steps; Test v.env in separate step
* cd into virtualenv
* Do not run on Python 2.7
* Build Nushell after formatting and clippy checks
* Add alias interning
Now, AliasId is used to reference aliases stored in EngineState, similar
to decls, blocks, etc.
* Fix wrong message
* Fix using decl instead of alias
* Extend also alias id visibility
* Merge also aliases from delta
* Add alias hiding code
Does not work yet but passes tests at least.
* Fix wrong alias lookup and visibility appending
* Add hide alias tests
* Fmt & Clippy
* Fix random clippy warnings in "which" command
* Fix "index out of bounds" when input to group-by is empty #4369
* Fix formatting #4369
* Adds test for empty input
Co-authored-by: Ray Henry <ray.henry@thermofisher.com>
Same rationale as in #4378
Also accelerate `grid`
before:
```
Command being timed: "./eager_nu -c for i in 0..100000 { echo whatever } | grid"
User time (seconds): 0.21
System time (seconds): 0.05
Percent of CPU this job got: 36%
Elapsed (wall clock) time (h:mm:ss or m:ss): 0:00.71
Average shared text size (kbytes): 0
Average unshared data size (kbytes): 0
Average stack size (kbytes): 0
Average total size (kbytes): 0
Maximum resident set size (kbytes): 48112
Average resident set size (kbytes): 0
Major (requiring I/O) page faults: 0
Minor (reclaiming a frame) page faults: 10580
Voluntary context switches: 266
Involuntary context switches: 2595
Swaps: 0
File system inputs: 0
File system outputs: 0
Socket messages sent: 0
Socket messages received: 0
Signals delivered: 0
Page size (bytes): 4096
Exit status: 0
```
after:
```
Command being timed: "./lazy_nu -c for i in 0..100000 { echo whatever } | grid"
User time (seconds): 0.14
System time (seconds): 0.05
Percent of CPU this job got: 33%
Elapsed (wall clock) time (h:mm:ss or m:ss): 0:00.60
Average shared text size (kbytes): 0
Average unshared data size (kbytes): 0
Average stack size (kbytes): 0
Average total size (kbytes): 0
Maximum resident set size (kbytes): 48272
Average resident set size (kbytes): 0
Major (requiring I/O) page faults: 1
Minor (reclaiming a frame) page faults: 10582
Voluntary context switches: 286
Involuntary context switches: 831
Swaps: 0
File system inputs: 56
File system outputs: 0
Socket messages sent: 0
Socket messages received: 0
Signals delivered: 0
Page size (bytes): 4096
Exit status: 0
```
