Schema inference over multiple files

[melvynator]

Use case
If you have multiple parquet files and are using schema inference, the inference of the schema will be done only on the first file.

Describe the solution you'd like

ClickHouse should look at all the files and do the union of the different schema.

[Avogar]

Duplicate of #55428?

[Avogar]

I will add it under a setting that will be disabled by default (because there can be thousands of files and reading schema of each will be not efficient at all)

[melvynator]

It's a duplicate indeed. Closing.