RFR: 7337: JMC fails to parse JFR with events from WebLogic Server [v2]

[Guru Hb]

> RC : NPE due to Invalid packageFieldIndex. 
> Disassembled the original jfr (attached in jbs) which had 3 chunks out of which the last chunk "WLF_3.jfr" with Event type (a) "com.oracle.weblogic.servlet.ServletRequestRunEvent" was causing the NPE. This could be a corrupt event or in complete event captured in the jfr.  
> This is a assertive fix and tried debugging the metadata parse (for any Ignored exception) and didn't find any noticeable place which can lead to events not indexed while collecting the events. 
> 
> After this fix compared the number of expected events of (a) with "jfr" tool in "jmc" (for WLF_3.jfr there were 32 events in (a) ) and didn't find any missing ones. 
> 
> Steps to re-produce NPE : load [WLS_3.jfr](https://bugs.openjdk.java.net/secure/attachment/95852/WLF_3.jfr.lz4)

Guru Hb has updated the pull request incrementally with one additional commit since the last revision:

  Updated copyright year

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Changes:
  - all: https://git.openjdk.java.net/jmc/pull/293/files
  - new: https://git.openjdk.java.net/jmc/pull/293/files/91016e08..586f9dab

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jmc&pr=293&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jmc&pr=293&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jmc/pull/293.diff
  Fetch: git fetch https://git.openjdk.java.net/jmc pull/293/head:pull/293

PR: https://git.openjdk.java.net/jmc/pull/293