fix(pretty-print): indent broken COALESCE and GREATEST arguments

[edjubert]

Problem

COALESCE and GREATEST/LEAST are rendered by the CoalesceExpr and MinMaxExpr nodes, which emit their argument list without the soft break after the opening parenthesis and without the indent region that emit_standard_function wraps around the arguments of a regular function call.

When the group breaks, the only remaining break opportunity is the one before a leading comma, so wrapped arguments land at the same indentation as the line that opens the call:

ON source_payment_types.value_en =
		COALESCE(rent_issuance_parameters_payment_types.value
		, translating.leases.rent_issuance_parameters_payment_type)

A regular function call in the same position already renders correctly.

Fix

Mirror emit_standard_function in emit_coalesce_expr and emit_min_max_expr: soft break after L_PAREN, indent region around the arguments, soft break before R_PAREN. A list that fits keeps rendering on a single line.

ON source_payment_types.value_en =
		COALESCE(
			rent_issuance_parameters_payment_types.value
			, translating.leases.rent_issuance_parameters_payment_type
		)

Tests

• new fixtures coalesce_expr_1.sql and min_max_expr_1.sql (leading commas, tabs, expanded layout) pin the broken rendering;
• existing snapshots window_function_group_200 and opr_sanity_80 are updated: they only move the affected COALESCE/greatest calls to the new layout;
• full pgls_pretty_print suite passes (566 tests), cargo clippy --all-targets clean.