Fix quoted tree path parsing in table views

[Caideyipi]

Problem

A table-model view whose tree prefix path contains a space fails when the path is written with quoted identifiers:

AS root."`tv143_cmp_3`"."`a b`".**

The parser produced root.tv143_cmp_3.``a b``.**, which is rejected as an illegal path.

Cause

The relational parser already preserves backticks returned by parseNodeString for identifiers that require them, but parsePrefixPath wrapped every node in another pair of backticks.

Fix

Preserve an existing backtick-wrapped node name and only add backticks when the parsed node name is not already quoted. Add parser and integration regressions covering the tree-to-table view query.

Tests

• mvn spotless:apply -pl iotdb-core/datanode
• mvn spotless:apply -pl integration-test -P with-integration-tests
• mvn compile -pl iotdb-core/datanode -am -DskipTests
• CreateViewPrefixPathTest (1 test, 0 failures)
• IoTDBTableIT#testCreateViewFromTreePathWithSpaces was attempted; the local integration environment could not start the ConfigNode and refused the connection.