16x16 icon size is too small on higher resolution displays

[starksm64]

Related to the existing request to improve the application icons: #475
either the default icon size should be 32x32, or there should be a preference option to set the displayed icon size.

Expected Behavior

It is very difficult to view the default icons, or add custom icons that can easily be understood what they are. I would like to either see the default icon size be 32x32 or have the ability to choose an icon display size from among a set of 16x16, 32x32, 48x48, 64x64.

Current Behavior

The current icon sizes are 16x16 and are simply very difficult to see clearly on displays like a 27" iMac.

Possible Solution

Currently the Metadata, Group and Entry classes have an icon scaling method that would need to be changed. Right now there is a test between a default and custom icon. Perhaps the Metadata class can be updated to simply handle the scaling/choice of the icon regardless of whether it was a default or custom icon.

Steps to Reproduce (for bugs)

Context

I have been moving my text based password store over to KeyPassXC and have found it difficult to create/assign meaningful icons to both groups and entries due to the low resolution that is supported.

Your Environment

KeePassXC - Version 2.1.4
Revision: 79ba3a2

Libraries:

• Qt 5.8.0
• libgcrypt 1.7.6

Operating system: OS X El Capitan (10.11)
CPU architecture: x86_64
Kernel: darwin 15.6.0

Enabled extensions:

• Auto-Type

[weslly]

Duplicate of #548.