CRTs: "Your Share" from revenue share shows 0 when it shouldn't be

[mochet]

Problem

• I own CRTs and the "Your share" column for each of them shows 0, but when I click "stake your tokens" it turns out that there is actually some reward available from the revenue share.
• The column appears to update after the revenue share has been claimed by the user

Solution

• "Your share" should show the amount available in $JOY from the revenue split or
• There should be a separate column showing the available revenue share in $JOY

[ikprk]

To be included in next release https://github.com/Joystream/atlas/pull/6331