Add warning when performing delegation actions that fees will be not attributed

[0xcadams]

According to LIP-36, any fees which are earned after a bonding manager action is performed will not be distributed due to the earnings algorithm. We should show a warning to users when they perform these actions to notify them that they will not be receiving rewards/fees for the remainder of the round.

https://github.com/livepeer/LIPs/blob/master/LIPs/LIP-36.md#specification-rationale

[rickstaa]

@ECWireless This behavior still occurs. Any action that claims earnings in the current round sets lastClaimRound = currentRound. Because LIP-36 uses cumulative factors and the next claim starts at lastClaimRound + 1, any fees added later in the same round (e.g. ticket redemptions) are skipped. Rewards are only missed if the transcoder has not yet called reward(), since rewards are minted once per round.

Affected actions
These actions claim to the current round via _autoClaimEarnings or updateDelegatorWithEarnings:

• bond, bondWithHint, bondForWithHint
• unbond, unbondWithHint
• rebond, rebondWithHint, rebondFromUnbonded, rebondFromUnbondedWithHint
• claimEarnings
• withdrawFees
• transferBond (receiver path)
  This can also occur during bridging. The L2Migrator calls pool.claim, which triggers transferBond and withdrawFees, producing the same effect. Since users typically already have funds on L2, this case is less common and can likely be ignored.

Warning logic
If any of these actions occur, display a warning. If the orchestrator has not yet called reward(), the delegator will lose rewards for the current round. If reward() has already been called, only the remaining fees for the current round will be forfeited.