RFR: 7581: Missing required plugins in JMC-RCP and JMC-RCP-plug-ins launcher

[Virag Purnam]

Below mentioned required plugins are missing in JMC-RCP and JMC-RCP-plug-ins launcher. Added them as an additional plugins.
org.eclipse.jetty.http (10.0.7)
org.eclipse.jetty.io (10.0.7)
org.eclipse.jetty.security (10.0.7)
org.eclipse.jetty.server (10.0.7)
org.eclipse.jetty.servlet (10.0.7)
org.eclipse.jetty.util (10.0.7)

![MissingRequiredPlugins](https://user-images.githubusercontent.com/97600378/161130307-0e56892a-b435-4db6-bf50-2b9fc121a2db.png)

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Commit messages:
 - 7581: Missing required plugins in JMC-RCP and JMC-RCP-plug-ins launcher

Changes: https://git.openjdk.java.net/jmc/pull/393/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jmc&pr=393&range=00
  Issue: https://bugs.openjdk.java.net/browse/JMC-7581
  Stats: 16 lines in 2 files changed: 14 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jmc/pull/393.diff
  Fetch: git fetch https://git.openjdk.java.net/jmc pull/393/head:pull/393

PR: https://git.openjdk.java.net/jmc/pull/393