Denoise show-all output

Currently the detailed output of `cargo crev v --show-all` is too noisy mostly because it includes many unneeded numbers due to e.g. unnecessary precision (`121015` is less informative than `.1m`) or `0`s

Below are a few suggestions re. how to make it look nicer and more informative:
- replace `0` with `␣` spaces
- change # downloads to whole millions (only show the fractional part if below `.5m` and show a max of one fractional digit, so 10345 would be `.0`)
- change `loc`s to thousands
- add a sub-header to add unit dimension (`K` and `M`) and `∑` totals (or maybe a simple `+` if `∑` breaks alignment with some fonts)

The ouput with these suggestions implemented would look like following
```
===AFTER===
status reviews issues owner downloads loc lpidx geiger flgs
∑ ∑ ∑ M ∑ K
none 1 2 10 48 .3 161 32 CB__
pass 2 4 2 40 43 .1 381 ____
none 9 1 5 89 .2 249 7 ____
none 2 3 .7 20 .2 132 CB__
none 12 2 1 21 3.4 32 1201 ____
none 2 10 46 .5 122 112 CB__
pass 3 8 2 72 94 .1 297 8 ____
===BEFORE===
status reviews issues owner downloads loc lpidx geiger flgs
none 0 1 0 0 0 2 10125K 47840K 323 161 32 CB__
pass 2 4 0 0 0 2 39838K 42837K 51 381 0 ____
none 0 9 0 0 0 1 5182K 89435K 252 249 7 ____
none 0 2 0 0 0 3 690K 20454K 202 132 0 CB__
none 0 12 0 0 0 2 979K 20714K 3463 32 1201 ____
none 0 0 0 0 0 2 9620K 46298K 529 122 112 CB__
pass 3 8 0 0 0 2 72455K 94052K 134 297 8 ____
```

* Please let us know:
* cargo-crev 0.23.2
* installed by downloading [this binary](https://github.com/crev-dev/cargo-crev/releases/download/v0.23.2/cargo-crev-v0.23.2-x86_64-pc-windows-msvc.tar.gz) from your release page and moved it to `...cargo\bin`
* Windows 10

Start by running `cargo crev v --show-all` and compare its detailed output with the proposed AFTER example in the issue. Trace the CLI's show-all output formatting, then make the displayed zeroes, download values, loc values, units, and totals match the requested presentation while preserving column alignment.

Written by the indexing model from the issue text.