Prevent table creation on non-empty location for Iceberg tables

[mdesmet]

Description

Is this change a fix, improvement, new feature, refactoring, or other?

Fix

Is this a change to the core query engine, a connector, client library, or the SPI interfaces? (be specific)

Change to Iceberg connector

How would you describe this change to a non-technical end user or system administrator?

Related issues, pull requests, and links

• Fixes Iceberg CREATE TABLE statement allows to create a table on a location already used by another Iceberg table #12573

Documentation

( ) No documentation is needed.
( ) Sufficient documentation is included in this PR.
( ) Documentation PR is available with #prnumber.
( ) Documentation issue #issuenumber is filed, and can be handled later.

Release notes

( ) No release notes entries required.
( ) Release notes entries required with the following suggested text:

# Section
* Fix some things. ({issue}`issuenumber`)

[alexjo2144]

If the directory exists, but is empty. Should we allow it? That seems reasonable to me

[findepi]

That can be useful and indeed is safe to do.

(except for concurrency, which we need to ignore anyway)

[findepi]

it's not only hdfsEnvironment.getFileSystem( what can throw IOE.
change message to

"Failed checking new table's location: " + location

[findepi]

use format

Suggested change

	throw new TrinoException(ICEBERG_FILESYSTEM_ERROR, "Cannot create a table on a non-empty location: " + location + ", " +
	"set 'iceberg.unique-table-location=true' in your Iceberg catalog properties to use unique table locations for every table.");
	throw new TrinoException(ICEBERG_FILESYSTEM_ERROR, format(
	"Cannot create a table on a non-empty location: %s, set 'iceberg.unique-table-location=true' in your Iceberg catalog properties " +
	"to use unique table locations for every table.",
	location));