3.18 icon updates

[nyalldawson]

Some newly introduced icons need rework prior to release:

• Point cloud layer icon: wrong style compared with other layer types (color vs monochrome). Also needs a variant in the data source manager monochrome+dark blueish style for use in data source manager
• Point cloud layer elevation properties: Reuse of poorly matching existing icon
• SAP/hana provider icons: need reworking to ideally remove the text strings, which are unreadable at certain sizes and bad for localisation
• need dedicated icons for fly/terrain 3d navigation modes
• point cloud "extent only" renderer needs an icon
• point cloud 3d "single color" renderer needs an icon
• merged features renderer: needs a proper icon instead of using the inverted polygon icon

[stefanuhrig]

I'll take care of finding an alternative for the HANA icons.

[stefanuhrig]

I've opened #41102 with new icons for SAP HANA.

[SrNetoChan]

@nyalldawson can you assign me to this one, please.

[gioman]

@nyalldawson can you assign me to this one, please.

done.

[nirvn]

Point one addressed here: #41394

[SrNetoChan]

@nyalldawson said:

• need dedicated icons for fly/terrain 3d navigation modes

Is this for the settings combobox? I don't see any icons on the toolbar (which would be welcome, I guess

[nyalldawson]

@SrNetoChan ignore those -- the buttons didn't get added yet, it will need to wait till 3.20

[SrNetoChan]

All other missing icons are now ready on #41490