Release 1.0-RC9

Bug fix release candidate, mostly related to cascading WMS and WMTS data sources, to seamlessly support HTTP proxy and configuration with jdbcconfig catalog backend.

What's Changed

• web-ui: add geostyler extension by @groldan in #153
• RemoteApplicationEvent event serialization fails on remote style infos by @groldan in #155
• Cascaded OWS Stores with HTTP proxy externalized configuration by @groldan in #154
• gs-jackson-bindings: add new property AttributeType.source:String by @groldan in #158
• Add vector tiles output format by @groldan in #159
• Web UI: hide unused global configuration UI controls by @groldan in #160
• Remove junit-vintage-engine where it's easy, full junit5 upgrade pending by @groldan in #161
• Initial gwc integration: standalone app and web-ui by @groldan in #162
• Make sure all known XStreamServiceLoaders are provided to GeoServerLoader by @groldan in #163
• gt-geojson is no longer a gt-wms dependency, it's been retire by @groldan in #165
• Fix WMTS stores and layers with jdbcconfig catalog backend by @groldan in #166

Full Changelog: v1.0-RC8...v1.0-RC9