Remove all panic and expect from executor codepaths

[ra0x3]

• A more comprehensive follow up to Invalid encoded byte error on beta-3-indexer #1096
• We have some panic and expect floating all around the tokio executor codepaths
• This is fine for debugging, but on production this will cause the service to crash
• Regardless of the case, in these executor codepaths, even if the operation fails, it needs to fail gracefully so the service can continue running
• If we encounter weirdness, we need to log it and keep moving
• Panic/except ok for when the service is started, but any codepath hit by a running tokio executor needs to be guarded

Additional context

• Some codepaths to possibly update
  • fuel_indexer::database
  • fuel_indexer::ffi
  • fuel_indexer::executor
  • fuel_indexer_schema::db::tables
  • fuel_indexer_schema::manager