Implementation of an Auto Layout for Row Column View Container

[rehans]

Implementation of an Auto Layout like described on this website: https://medium.com/timeless/figma-updates-new-auto-layout-alignments-ec6cb134aea4

You can access the new layouts in the VSTGUI Live editor Row Column View Container: equal-size-layout (equal-size-layout could be renamed as the new auto layout also allows different view sizes of children).

• auto layout is an extension of CRowColumnViews layout options
• new options top-left, top-center, top-right, middle-left, middle-center, middle-right, bottom-left, bottom-center, bottom-right integrate into the existing mechanism (the old ones are working as usual)
• Row Column View Container : spacing between views is maintained
• new unit tests for CRowColumView layout created
• existing RowColumViewCreator have been fixed (by adding the new options)

[rehans]

@scheffle I added some documentation to explain what AutoLayout does.