Add missing icon sizes

Summary:
Add missing scalable icon sizes

BUG: 384473

Test Plan:
Add missing scalable icon sizes at index.theme. If not all size are covered by scalable icons some desktop environment other than PLASMA may show icons not properly scaled.

See also bug #384473 for more detailed explaination and screenshot
https://bugs.kde.org/show_bug.cgi?id=384473

Update:
From the MATE Desktop environment you may use 'Appearance' (the binary is (/usr/bin/mate-appearance-properties) to modify its look-and-feel. There is not a Breeze theme listed there here but from the 'Theme' tab you may click the 'Customise...' button and from the new window you may select 'Breeze' in 'Controls', 'Pointer' and 'Icons' tabs.

{F5404548}

Then restart MATE to see the applied changes. Here is how MATE desktop appears with Breeze icons before the changes.

{F5402571}

As you may see (scalable) icons from Breeze theme are bigger than others (which are .svg icons too). In caja application this is even more evident especially for 'computer' icon

{F5402644}

After I inspected the caja code I found it uses scalable icons and I found the problem is Breeze does not provide for some icon sizes for some scalable icons required  by caja so it uses a bigger sized icon (all works fine with MATE default theme, of course). So I modified the Breeze index.theme as reported here and ,as you may see from the screenshots below, all icons are of the right size

desktop
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caja
{F5403202}

I used the fixed Breeze theme both in PLASMA and LXQt and I not noticed any differences from before to after so I believe my changes are not dangerous for other DE.

Reviewers: #breeze, #vdg, jensreuterberg, #frameworks, hein, mandian

Reviewed By: hein

Subscribers: andreask, hein, ngraham, cfeck, #frameworks

Tags: #frameworks, #breeze

Differential Revision: https://phabricator.kde.org/D7810