Negative currencies put their sign on the wrong side in RTL

[sirbrillig]

Switching the browser to use RTL text direction (eg: by running document.dir = 'rtl' in the console) reverses the symbols around formatted prices, like the currency symbol. However, if the number is negative, the negative sign (-) should always (I think?) appear on the left side of the number. There are ways to mitigate this, described more in https://github.com/Automattic/wp-calypso/pull/71387#issuecomment-1370423405

[sirbrillig]

Just to copy from the other issue,

This works correctly from the BIDI algorithm point of view since the minus sign has weak directionality and with base RTL direction it'd be incorrectly put to the right of the numbers. The easiest way to fix it would be to explicitly wrap the minus sign and all the numbers in an LTR run, like <bdo dir="ltr">-140.00</bdo> €, or use some other approach from https://www.w3.org/International/questions/qa-bidi-unicode-controls.

[michaeldcain]

From planning:

On the front-end, since we're consolidating behind formatCurrency, we should add an additional method that generates the HTML string and then update it wherever we're using formatCurrency. Since this bug has likely always been around, it's not likely high priority, but could be dealt with while doing other i18n currency updates.