Phpstan hasn't identified any errors in Samples in a long time. But, as it turns out, one particular error is suppressed:
```
Variable $helper might not be defined.
```
This error would be generated by almost all samples, and the errors that it suppresses will become problematic if we move to Level 10. We are not yet committed to doing that, but it is pretty easy to write a script to change the samples so that error no longer happens, and there isn't really any reason to delay doing so. The results of that script constitute this PR.
* Let Phpstan Run on Samples
Phpstan currently analyzes all source and test members. We already run phpcs and php-cs-fixer on samples as well. I would expect that samples are often used as templates for code in userland; it behooves us to be at least as careful with those members as for the others which are already being analyzed. Aside from 1300+ messages `Variable $helper might not be defined.`, which will be suppressed in phpstan.neon.dist, there are really only a few changes needed for sample members, so that part of the code base was already in good shape, and is now even better. No annotations were needed.
* Scrutinizer 2 out of 3
1 false positive, now suppressed; fix other 2.
* Remove Dead Code
* Very Minor Changes
* Add infra
* Chart Dynamic Title and Special Font Properties
Fix#3797. Excel allows a Chart Title to be a formula, albeit a very rigidly limited one. It can only be a reference to a single cell, and the worksheet name must be specified, and the column and row must be absolute. Methods are added to Chart/Title to accommodate this (and styling for it). This will be handled for input/output for Xlsx, and for output for Html.
The sample file which was submitted with this issue demonstrated that something else was missing. When setting the font for a chart title in Excel, you can specify all-caps or small-caps, options not available for most cell formatting. These are now added.
The sample file also fell into the category of spreadsheets which lose one or more charts when converted to Html. I have redone the "extend rows and charts" logic in Html Writer. It is now clearer (I hope) and more efficient, and hopefully this problem will not arise again.
* Scrutinizer 50/50
One false positive, one correct "unused parameter".
oleibman
MarkBaker
Adrien Crivelli