ability to show dif map directly in shader level

[Lyzdeika]

1.standart mat editor. please correct and add ability to show difuse map in viewport in shader level - not in maps. now it is blocked and only accesible in difuse texture level . it is anoyng to go all the time in texture and there click show map in viewport - should be simplier to clock in shader level and show difuse text.

[Ondra]

Done

[Juraj]

Fantastic :- ) !!