[AlertFieldLevel] Vertically centering text, 5px margin between icon and text

[shindigira]

Delayed

Requires a DS change first.

[billhimmelsbach]

Heyo @shindigira! I know you're still working on this, but just wanted to let you know that after today's discussions, these three TODOs are going to be fixed at the source in the DS first instead of in the DSR in this PR:

• Change Margin between icon and text to 5px in AlertFieldLevel
• fix the centering icon in Alert (not fieldlevel) (Delay LOW PRIORITY: [context](figma comment that we will revisit this change later))
• Error dotted line around checkbox/textinput

The first two of those TODOs (the margin and centering the icon) will also be de-prioritized and moved to the backlog for now too. Should make this PR a little smaller! 🤞