…key.h

71c824e cleaned up and added missing "include" statements for pubkey.cpp and pubkey.h (William Bright)

Pull request description:

  #### Problem:
  Many symbols in the files were undefined and causing issues when I was working on building independent sections of the codebase. The hidden imports from the "secp256k1" library was a particular pain point.

  The other standard and missing includes are following best practices and will help with refactoring, build process and others.

  #### Changes:
  Clean up and declared imports/include for `pubkey.cpp` and `pubkey.h`

ACKs for top commit:
  jnewbery:
    utACK 71c824e
  laanwj:
    Code review ACK 71c824e

Tree-SHA512: bce605cfde24d8e3be82a596cabab7a8577fec0aef7c5e6f7a56603357046d8e8dea11ac8e3dbe79600550291be7784e35c7a55ebf40b46525b8949e4bedae96

fa74bfc fuzz: Run const CScript member functions only once (MarcoFalke)

Pull request description:

  Those functions should be O(N) in the input size (or maybe worse, I didn't check), so if the fuzz input dictates to run them N times, the complexity is N^2.

  Fix this by calling them only once.

  Can be reviewed with: `--ignore-all-space  --word-diff-regex=.`

  Input: https://github.com/bitcoin/bitcoin/files/6464685/clusterfuzz-testcase-minimized-input.log

  Hopefully fixes https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=34101

ACKs for top commit:
  practicalswift:
    cr ACK fa74bfc: patch looks correct, rationale makes sense and patch touches only `src/test/fuzz/`

Tree-SHA512: d579f7a2103ec154bf482a872142e55a1d9e7673d33a22a4c4230186fdd1b6618846463f4e25941031cc8c4bd1ea8d06cb49ae1bb1ec4af115497f5e5de1e19c