XWIKI-13153: Add ability to set background colors for the plot and non-plot areas

xwiki-platform-core/pom.xml

...nderer/src/main/java/org/xwiki/chart/ChartCustomizer.java

...enderer/src/main/java/org/xwiki/chart/ChartGenerator.java

...n/java/org/xwiki/chart/internal/ColorChartCustomizer.java

.../java/org/xwiki/chart/internal/DefaultChartGenerator.java

...java/org/xwiki/chart/internal/DrawingSupplierFactory.java

...chart-renderer/src/main/resources/META-INF/components.txt