Update Cells.SVG image, as previous versions was broken in Firefox

[#47730701]
Add polymerase to the DNA intro animation

[#47730701]
Choose a random starting point along a circle for new mRNA segments

[#48485973]
Limit available starting positions of new mRNA segments to top and bottom sides

[#48485973]
Ensure that viewport is centered during DNA intro animation

[#47730701]
Add initial version of translateStep() method to genetic controller

[#47731663]
Add translateStep() method to Scripting API

[#47731663]
Update "Modeling Translation" interactive

[#47731663]

Change it so it's easier to test further work connected with
translation.
Implement first part of the DNA translation intro animation

[#47731663]
disable markNearbyDataPoints

[#48485385]
remove 1% padding around responsive-content