Treat ClickHouse range() as a function when followed by a parenthesis

[cpruijsen]

Remap ClickHouse RANGE to a function name when the next token is (. ClickHouse function names are case-sensitive. With keywordCase: "upper", SELECT range(32) stays range(32) instead of RANGE (32), which ClickHouse rejects:

Code: 46. DB::Exception: Function with name `RANGE` does not exist.
Maybe you meant: ['range','rand']. (UNKNOWN_FUNCTION)

Fixes #980.

RANGE is a reserved keyword. range() is omitted from the functions list because RANGE is also a window-frame word. postProcess already remaps SET(100) to a function name when the next token is (. RANGE now uses that same neighbour check. Default functionCase is preserve, so the original range spelling is kept.

{ROWS | RANGE} BETWEEN remains a reserved keyword phrase, so window frames are unchanged.

Alternative: add range to clickhouse.functions.ts. That would let funcNameToIdent turn bare RANGE into an identifier (for example RANGE UNBOUNDED PRECEDING) and would fight the existing comment on the functions list. Happy to switch if that is preferred.

Test plan

• SELECT range(32) with keywordCase: "upper" keeps range(32)
• RANGE BETWEEN in a window frame still formats as a keyword phrase
• ClickHouse dialect tests (test/clickhouse.test.ts)