Stabilize width of article list

[barijaona]

With the "Load Full HTML" setting enabled, changes of article list width were sometimes seen. The problem was reported by @josh64x2 in #1596 and I have also seen it with some sites.

We modify holding priorities for subviews of SplitView2 Need feedback to make sure this change is good enough for any website.

[barijaona]

Seems to work better with old browser than with new browser.

Any ideas ?

[josh64x2]

OK I was also unable to fix the vertical layout in master until I turned off the new browser preview, so it wasn't caused by this PR.

I do have reliable way of reproducing a broken Vertical layout though so let me try and debug this over the next couple of days!

[barijaona]

It appears to me that, for some unknown reason, some WkWebView will get higher content compression resistance priority / content hugging priority than legacy WebView

[barijaona]

I haven't had a chance to debug yet, but now the vertical layout is broken and I'm unable to resize it:

And it's worst on 10.12… 😟

[barijaona]

New version submitted. I have tried many approaches, but could not find anything simpler that covers all the combinations I tested. Tested with vertical layout and "Load full HTML" enabled on feeds https://www.lemonde.fr/rss/une.xml and http://www.confidential-renault.fr/?rss=RSS You need to test with a combination of feeds with and without Load full HTML" enabled.

[barijaona]

I do have reliable way of reproducing a broken Vertical layout though so let me try and debug this over the next couple of days!

Do you reproduce the problem with my latest version ?

[barijaona]

I am currently unable to test on older versions of macOS. If anyone can provide feedback, it will be welcomed.

[josh64x2]

I will test this tomorrow and let you know how it goes!