Fix arrows size when expand/collapse a group

[dmaslenko]

Let's have the same ratio for both vertical and horizontal direction.

Fixes #8335 user interface bug.

Screenshots

Classic style always has the same sizes:

Let's have the same sizes for custom app styles:

Reducing the ratio leads to have small down arrow and big right one: const qreal ArrowBaseRatio = 0.4

Testing strategy

• Have an entry group(s)
• Switch to all supported themes
• Verify the group tree arrows

Type of change

• ✅ Bug fix (non-breaking change that fixes an issue)

[droidmonkey]

The code that draws the arrow is so bad. Maybe this was the missing piece when we tried to fix the arrow size in compact mode and also tried to reduce the indent

[dmaslenko]

The bug is reproducible in both modes.
The arrow size does not impact much on indention, few saved pixels horizontally don't play key role.
This is the compact mode:

If we really want to have smaller arrows we need to scale like this but keep the ratio=1:

            const qreal ArrowBaseRatio = 1.0;

...

            irw *= 0.7;
            irh *= 0.7;

Compact mode:

Not compact mode:

Let me know is it better?

[droidmonkey]

No keep the arrow the original size, the ratio fix is good

[droidmonkey]

I changed the ratio to 0.9, 1.0 produced rather pointy arrows.