Add new typo size "L" to design tokens

[mcilurzo]

jobs to be done:
– check if somewhere the style "L" is still used, replace it with "XL" if necessary.
– add new size "L" (specification in figma)

https://www.figma.com/file/mWknI2rC5DJmOgRO61WKai/Lyne-Design-Tokens?node-id=1206%3A7067