Improve error message when wallet runs against syncing index

[casey]

If you run a wallet command while the index is syncing, you'll get "error: wallet failed to synchronize with ord server", we should instead either hang, with a message like "waiting for ord server to sync", or give an error message that includes the server height and the bitcoind height.

[lalotrage]

If you run a wallet command while the index is syncing, you'll get "error: wallet failed to synchronize with ord server", we should instead either hang, with a message like "waiting for ord server to sync", or give an error message that includes the server height and the bitcoind height.

Looks silly but usefull, it took me sometime to understand that msg the first time I got it.

[gus4rs]

So the idea is to let wallet and server compete for the index lock? The index lock is held for a VERY long time, making using a wallet a nightmare