RFR: 8289939: Add flag to restrict public exponent as described in SP 800-56B

[Kevin Driver]

[SP 800-56B](https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-56Br2.pdf) stipulates that the publicExponent e "shall" be 65,537 ≤ e < 2^256

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Commit messages:
 - initial commit for JDK-8289939

Changes: https://git.openjdk.org/jdk/pull/9413/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=9413&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8289939
  Stats: 18 lines in 1 file changed: 18 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/9413.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9413/head:pull/9413

PR: https://git.openjdk.org/jdk/pull/9413