bud.js v6.12.2 & some build improvements

• bud.config.js: bud.wpjson.settings replaced with bud.wpjson.set
• jsconfig.json: Added simple comments
• app.js: Safer HMR handling

See #3128 — props @kellymears

Additional changes

• Use wp i18n update-po for updating PO files by @strarsis (#3081)
• Fix: core/button block style by @kellymears (#3130)

Full Changelog: v10.5.1...v10.6.0