feat(format): add the clauseBodyStyle and isolateSemicolon options

[edjubert]

What

Option	Default	Values
clauseBodyStyle	"break"	"break", "compact"
isolateSemicolon	false	boolean

clauseBodyStyle=compact

Keeps the first element of a clause body on the keyword line instead of starting a new one.
Applies to WHERE/HAVING/ON conditions and to FROM/WINDOW bodies:

-- break (default, today's output)
from
	staging.buildings
where
	staging.buildings.construction_year > 1950

-- compact
from staging.buildings
where staging.buildings.construction_year > 1950

isolateSemicolon=true

Puts the terminating semicolon on its own line, but only when the statement already spans several lines - a one-line statement keeps its ; attached:

select
	staging.buildings.id,
	staging.buildings.construction_year
from
	staging.buildings
;

Why

compact is the shape most hand-written SQL in data pipelines already uses, and it saves a line per clause on wide screens.
The isolated semicolon is what makes a multi-statement migration file diff cleanly: adding a statement at the end no longer rewrites the previous statement's last line.

Implementation

clauseBodyStyle is resolved in renderer.rs when a clause group is opened, and in select_stmt.rs / nodes/mod.rs for the clauses that emit their own break.
isolateSemicolon is a renderer decision taken once the statement is known to be multi-line.

Wiring: pgls_configuration (--clause-body-style, --isolate-semicolon), pgls_workspace settings, docs/features/formatting.md, docs/schema.json.

Tests

Three new fixtures (compact_clause_condition, compact_from_clause, isolated_semicolon) with snapshots.
Defaults leave every existing snapshot untouched.

The two preparatory commits

The first two commits of this PR are shared, byte for byte, with the three other formatter-option PRs open alongside it:

• #795 — commaStyle / logicalOperatorPlacement
• #797 — layout
• #798 — castStyle

The shared commits are:

• test(pretty-print): allow per-fixture format configuration
• refactor(pretty-print): thread the format config into the emitter

They are carried in each PR so every option remains independently reviewable and mergeable.
Whichever PR lands first, I will rebase the other three to remove the duplicate commits.

Merge them in whatever order suits you; nothing here depends on the others.