RFR: JMC-7798: Make the frame type extensible [v3]

[Jaroslav Bachorik]

> This change allows the JMC parser users to consume frames with the type set to non-standard values (eg. from async-profiler).
> 
> The hard-wired enum approach is replaced with a hybrid solution keeping the standard types in enum-like structure and using a cache for the non-standard types. This allows being fairly flexible when dealing with new frame types while keeping full backward compatibility.

Jaroslav Bachorik has updated the pull request incrementally with one additional commit since the last revision:

  Addressing review comments

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Changes:
  - all: https://git.openjdk.java.net/jmc/pull/401/files
  - new: https://git.openjdk.java.net/jmc/pull/401/files/fddc5b68..1b2d3556

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jmc&pr=401&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jmc&pr=401&range=01-02

  Stats: 160 lines in 5 files changed: 100 ins; 54 del; 6 mod
  Patch: https://git.openjdk.java.net/jmc/pull/401.diff
  Fetch: git fetch https://git.openjdk.java.net/jmc pull/401/head:pull/401

PR: https://git.openjdk.java.net/jmc/pull/401