Nodes should not be able to unbond when in the wrong state.

[GrassRootsCrypto]

Description

Current

Can Unbond a node in any state, e.g. active. THORNodes returns an error which is not seen by the user. Modal hangs (#192) so the user is confused about what is going on.

Desired

Do not allow Nodes Operators to Unbond when Nodes are in the following status:

1. Active
2. Ready
3. Unknown
4. Standby when retiring

Active and Ready Code Ref
https://gitlab.com/thorchain/thornode/-/blob/develop/x/thorchain/handler_unbond.go?ref_type=heads#L73

Standby when retiring Code Ref
https://gitlab.com/thorchain/thornode/-/blob/develop/x/thorchain/handler_unbond.go?ref_type=heads#L137

The user should be informed when on the Unbond page if they cannot Unbond. Users can only unbond if their node is in the standby state and their node is retired.

A Retiring Node

Retring is not Node Status, it is a state a node is in during a churn. It is migrating funds from an old vault to a new vault and thornode prohibits unbond till the migration is completed.

Something like the below should be implemented to see if a node in the Standy state is retiring.

If NodeStatus === NodeStatusEnum.Standby { 
  Get Vaults Info from https://thornode.ninerealms.com/thorchain/vaults/asgard - xchainjs should have this
  
  Then do
  
  function checkNodeRetirement(nodeAddress, vaultsData) {
      for (const vault of vaultsData) {
          if (vault.membership && vault.membership.includes(nodeAddress)) {
              return true; // Node is Retiring, cannot unbond
          }
      }
      return false; // Node is not Retiring, unbond is allowed. 
  }

}