Never italicise Farsi

[twinlensreflex]

Is your feature request related to a problem? Please describe.
replaced PR 2548, see discussion on PR for why
We want to use psammead-font-styles across Simorgh to ensure that we are not italicising Farsi.

Describe the solution you'd like

• Pull in work in psammead which disabled italics in persian

• this means:
  • Updating psammead-styles to version 1.1.0 if/where needed (see work in psammead to de-italicise caption)
  • using functions like getSansItalic where we currently use font-style: italic
• Rethinking our approach to <i> and <b> tags in Fragment

Describe alternatives you've considered
Fixing these issues by using

 [lang=fa] & {
    font-style: normal;
  }

but the approach in this ticket removes duplication and will handle this for more languages than just farsi.

Testing notes

• Farsi article c19v65z3lg5o has italics in the headline in the data (on فوتبال )

Dev insight: Will Cypress tests be required or are unit tests sufficient? Will there be any potential regression? etc

Additional context
Add any other context or screenshots about the feature request here.

[twinlensreflex]

Possibly can be closed on this work:
#2548
BBC-archive/psammead#376
#1731

[twinlensreflex]

I've updated #1731 with the information from this issye and will now close this issue