[paimon] Align error msg when altering table properties

[nastra]

Purpose

This aligns the error msg that is thrown when altering table properties of a non-existing table. Previously the error msg contained a paimon-specific identifier and I've changed it to show the TablePath instead. I've also added a test

Brief change log

Tests

Added a unit test to verify the error msg

API and Format

Documentation

[Copilot]

Pull request overview

This PR aligns the error message format when altering properties of a non-existing table. The error message now uses the Fluss TablePath format instead of the Paimon-specific identifier format, and the message text is updated from "not exists" to "does not exist" for grammatical correctness.

Key changes:

• Updated error message to use TablePath instead of Paimon Identifier format
• Corrected grammar in error message from "not exists" to "does not exist"
• Added comprehensive test coverage for the error message in both scenarios (non-existing database and non-existing table)

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
PaimonLakeCatalog.java	Refactored alterTable method to accept TablePath parameter and convert to Paimon format internally, ensuring error messages display the Fluss table path
PaimonLakeCatalogTest.java	Added test cases verifying the error message format when attempting to alter properties of non-existing tables

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[LiebingYu]

@nastra Thanks for the PR. LGTM overall, but I think we can also change the msg in createTable.

    private void createTable(Identifier tablePath, Schema schema, boolean isCreatingFlussTable)
            throws Catalog.DatabaseNotExistException {
        try {
            // not ignore if table exists
            paimonCatalog.createTable(tablePath, schema, false);
        } catch (Catalog.TableAlreadyExistException e) {
            try {
                Table table = paimonCatalog.getTable(tablePath);
                FileStoreTable fileStoreTable = (FileStoreTable) table;
                validatePaimonSchemaCompatible(
                        tablePath, fileStoreTable.schema().toSchema(), schema);
                // if creating a new fluss table, we should ensure the lake table is empty
                if (isCreatingFlussTable) {
                    checkTableIsEmpty(tablePath, fileStoreTable);
                }
            } catch (Catalog.TableNotExistException tableNotExistException) {
                // shouldn't happen in normal cases
                throw new RuntimeException(
                        String.format(
                                "Failed to create table %s in Paimon. The table already existed "
                                        + "during the initial creation attempt, but subsequently "
                                        + "could not be found when trying to get it. "
                                        + "Please check whether the Paimon table was manually deleted, and try again.",
                                tablePath));
            }
        }
    }

[nastra]

@LiebingYu I've updated the error msg of createTable to include TablePath instead of Identifier

[luoyuxia]

@nastra Thanks. LGTM