RFR: 8286908: ECDSA signature should not return parameters [v2]

[Weijun Wang]

> Let ECDSA's `engineGetParameters()` always return null. At the same time, remove the remembered `sigParams` field. One behavior change is that after calling `setParameter()`, one can call `init()` again with a key using different parameters. I think this should be allowed since we are reusing the signature object with a brand new key.
> 
> `setParameter` is kept unchanged to be able to deal with certificates still having parameters after the signature algorithm object identifier. See https://bugs.openjdk.java.net/browse/JDK-8225745.
> 
> Also added SHA1withECDSA to the no-NULL list in `KnownOIDs`.
> 
> All security-related tests passed.

Weijun Wang has updated the pull request incrementally with one additional commit since the last revision:

  will not read params for ECDSA

-------------

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/8758/files
  - new: https://git.openjdk.java.net/jdk/pull/8758/files/b13de5a9..aceeb4a7

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=8758&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=8758&range=00-01

  Stats: 13 lines in 2 files changed: 1 ins; 8 del; 4 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8758.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8758/head:pull/8758

PR: https://git.openjdk.java.net/jdk/pull/8758