Add a UI for gateways to manage deposit/reserve from the Explorer

Nobody has claimed this yet.

### Is your feature request related to a problem?

The only UX for gateways to manage deposit/reserve is via livepeer_cli. Now that gateways are featured on the explorer, there should be a user interface for executing deposit/reserve funding and unlock actions. This will improve user accessibility to the network and provide another entry point to the network for demand.

### Describe the solution you'd like

I suggest the Broadcasting tab should display the gateway admin form in place of the current delegator form. When the Delegating tab is selected, the current delegator form would show

### Describe alternatives you've considered

_No response_

### Additional context

The `livepeer_cli` UX for removing broadcaster funds is also rather poor. The below issues might be easier to address from the explorer

> Issue 1. Protocol requires user to wait for end of round (not much we can do there)
Invoke "deposit broadcasting funds" (ETH)
Invoke "unlock broadcasting funds"
Invoke "cancel unlock of broadcasting funds"
Invoke "withdraw broadcasting funds"

Issue 2: `livepeer_cli` Option 12 does not allow user to set how much to unlock. It is unlock everything and deactivate or leave it there to spend
> 12
Current Deposit: 0.057953535353535356 ETH
Current Reserve: 0.04 ETH
Current Round: 4174
If you initiate the unlock period now, you will be able to withdraw at round 4176
Would you like initiate the unlock period? (y/n) - > n

Start by locating the Explorer's Broadcasting and Delegating tabs and the current delegator form. Compare the requested gateway admin flow with the livepeer_cli deposit, reserve, unlock, cancel-unlock, and withdraw actions. Done means gateways can manage these funding actions from the Broadcasting tab while delegators retain their existing form in the Delegating tab.

Written by the indexing model from the issue text.