Allow space-separated multiple url_prefix

[dhruvkelawala]

When we were using SentryWebpackPlugin(), we had the following code in include

 new SentryWebpackPlugin({
        authToken: process.env.SENTRY_AUTH_TOKEN,
        project: process.env.SENTRY_PROJECT,,
        org: "process.env.SENTRY_ORG,,
        release: process.env.npm_package_version,
        include: [
          {
            paths: ["./dist"],
            urlPrefix: "~/",
          },
          {
            paths: ["./sourcemaps"],
            urlPrefix: "~/sourcemaps",
          },
        ],
        debug: true,
        ignore: ["node_modules"],
        validate: true,
        cleanArtifacts: true,
      }),

However, this github action doesn't support multiple urlPrefix. We are working on an web-extension, so we cannot ship sourcemaps in dist as it increases the bundle size. So it would be great if we could pass url_prefix as space-separated string values corresponding to sourcemaps.