Remove lighter font weights on new dashboard

[viddo]

Fixes #2335

Edit: Changed approach after review:

• Remove lighter font-weight on font-sizes <= 13px
• Apply special text-rendering overrides for smaller fonts to not have such a bold look.

New screenshots:

[viddo]

@carlostallon @xavijam @saleiva as instructed in the issue I've removed the lighter fonts. I'd suggest we do a deploy on staging (none available yet) to really check if this solves it. Thoughts?

[xavijam]

It is a pity we have to "remove" it, but if some browsers don't render properly, this is the best solution.

[viddo]

bump, any feedback on this please?

[saleiva]

Not the same, but... let's go with it :)

[piensaenpixel]

If we remove the lighter fonts, may be we could try use this property of css
text-rendering: optimizeLegibility;

[viddo]

@saleiva @piensaenpixel @xavijam changes based on feedback, see PR desc for screenshots. also deployed on staging (ded02) if you want to have a look yourself. cc @Kartones

[viddo]

Screenshot from kartones with the new changes:

OK?

[xavijam]

🇯🇵

[Cartofante]

Frontend tests were OK 👍 (details)