Unify Client Interface for Writing Tables

[genematx]

This allows one to create and write appendable tables using the same write_table interface on the Tiled client (instead of create_appendable_table + append_partition), as used for the usual (fixed) tables. If the server does not support SQLStorage for tabular data, the client falls back to writing to Parquet, as before.

Checklist

• Add a Changelog entry
• Add the ticket number which this PR closes to the comment section

[danielballan]

I'm very much on with improving the ergonomics here; I agree they need improving.

Something appeals to me about the two-step process for creating appendable tables: first you declare the schema, and then you start writing data. It aligns with CREATE TABLE and INSERT INTO being distinct phases. But maybe the argument for exposing this to the user/client is not a strong as I think, and we should just make this work the same as the others, where we do a POST and then PUT(s) for the user. Let's talk through the implications in a conversation.