Add Datamodder SQL Formatter (FormatSQL) plugin

[dm-utils]

Plugin

Datamodder SQL Formatter (folder-name: FormatSQL) — a SQL formatter, minifier and dialect converter for Notepad++.

• Repository: https://github.com/dm-utils/formatsql
• Release used: https://github.com/dm-utils/formatsql/releases/tag/v1.3.1.2
• License: MIT
• 64-bit only (this PR adds an entry to src/pl.x64.json only)

Validation performed

• Entry validated against pl.schema with jsonschema (whole file, including this entry, passes)
• id is the SHA-256 of the release zip, confirmed against GitHub's own asset digest for the release
• Entry inserted in alphabetical order by folder-name (after FoldingLineHider, before GedcomLexer)
• Plugin itself manually built, installed and exercised in a real Notepad++ install (not via Plugin Admin's list mechanism)
• Not yet tested via Notepad++'s Plugin Admin local-list install flow specifically — happy to do that and report back if that's expected before review.