Calling APIs for getters or to broadcast signed transaction

When broadcasting a signed tx to chain:

1. The list of API url in Admin is set in priority order

2. Fetch the list

3. Call the first server in the list

   1. Response successful

      1. Return value and stop further execution

   2. Response contains unexpected error or no response for 5 sec

      1. Call the second server in the list

      2. Repeat

4. If the last server in list contains unexpected error or no response for 5 sec

   1. Show Generic Error