view: use Auspice v3 CLI args

[joverlee521]

Noticed the deprecation warnings after updating my local runtimes to Auspice v3.

[warning]       [DEPRECATED] Instead of 'auspice ... --datasetDir auspice/' please use 'auspice ... auspice/'
[warning]       [DEPRECATED] Instead of 'auspice ... --narrativeDir .' please use 'auspice ... .'

See nextstrain/auspice#1967

[victorlin]

I think this will be addressed by #541

[joverlee521]

Ah, nice! I totally missed that PR.