Don't error when importing samples fails against one of a list of clusters

[Westwooo]

'buckets load sample' can be used to import sample data into multiple clusters/databases at the same time. When this fails the call will error out and no more samples will be imported. The behaviour should be changed so that instead of erroring out the failure is returned to the shell and other imports are attempted. For example if importing to two clusters A and B and the import fails on A but succeeds on B we should see:

╭───┬─────────┬─────────────────────────────────────────────────────────────────────────────────────────────────────────────────|
│ # │ cluster │    sample     |             taskId                   |                          status                          |                                              
├───┼─────────┼───────────────|──────────────────────────────────────|──────────────────────────────────────────────────────────|
│ 0 │ A       │  travel-sample| 991a2e9c-6993-48e3-b8b0-2d05811e7a8c | failure - Sample bucket travel-sample is already loaded  |
|───┴─────────┴─────────────────────────────────────────────────────────────────────────────────────────────────────────────────|
| 1 | B       | travel-sample | 817k9kj1-1823-1da9-ba12-39amcudoqo12 |                         success                          |
╰───┴─────────┴─────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯