Consume SVG rasterizer via capability in SWT tests bundle

Currently, requiring an SVG rasterizer needs manual placement of an
according fragment providing a rasterizer on the classpath. With this
change, requiring SVG support can be defined explicitly via a required
capability that is provided by the according SWT fragment.

Contributes to
eclipse-platform#1944

Author: HeikoKlare

bundles/org.eclipse.swt.svg/META-INF/MANIFEST.MF

@@ -11,3 +11,6 @@ Import-Package: com.github.weisj.jsvg;version="[1.7.0,2.0.0)",
  com.github.weisj.jsvg.geometry.size;version="[1.7.0,2.0.0)",
  com.github.weisj.jsvg.parser;version="[1.7.0,2.0.0)"
 Export-Package: org.eclipse.swt.svg
+Provide-Capability: osgi.implementation;
+    osgi.implementation="swt.svgrasterizer";
+    version:Version="1.0"

tests/org.eclipse.swt.tests/META-INF/MANIFEST.MF

@@ -20,3 +20,4 @@ Require-Bundle: org.junit;bundle-version="4.13.2",
 Eclipse-BundleShape: dir
 Bundle-RequiredExecutionEnvironment: JavaSE-17
 Automatic-Module-Name: org.eclipse.swt.tests
+Require-Capability: osgi.implementation;filter:="(osgi.implementation=swt.svgrasterizer)"