Merge #17691: doc: Add missed copyright headers

fac86ac7b3 scripted-diff: Add missed copyright headers (Hennadii Stepanov)
6fde9d5e47 script: Update EXLUDE list in copyright_header.py (Hennadii Stepanov)
1998152f15 script: Add empty line after C++ copyright (Hennadii Stepanov)
071f2fc204 script: Add ability to insert copyright to *.sh (Hennadii Stepanov)

Pull request description:

  This PR improves `contrib/devtools/copyright_header.py` script and adds copyright headers to the files in `src` and `test` directories with two exceptions:
  - [`src/reverse_iterator.h`](https://github.com/bitcoin/bitcoin/blob/master/src/reverse_iterator.h) (added to exceptions)
  - [`src/test/fuzz/FuzzedDataProvider.h`](https://github.com/bitcoin/bitcoin/blob/master/src/test/fuzz/FuzzedDataProvider.h) (added to exceptions)

  On master 5622d8f315:
  ```
  $ ./contrib/devtools/copyright_header.py report . | grep zero
    25 with zero copyrights
  ```

  With this PR:
  ```
  $ ./contrib/devtools/copyright_header.py report . | grep zero
     2 with zero copyrights
  ```

  ~I am uncertain about our copyright policy with `build_msvc` and `contrib` directories content, so they are out of scope of this PR.~

ACKs for top commit:
  MarcoFalke:
    ACK fac86ac7b3

Tree-SHA512: d7832c4a7a1a3b7806119775b40ec35d7982f49ff0e6199b8cee4c0e0a36e68d51728b6ee9924b1c161df4bc6105bd93391b79d42914357fa522f499cb113fa8

test/lint/lint-locale-dependence.sh

@@ -1,4 +1,7 @@
 #!/usr/bin/env bash
+# Copyright (c) 2018-2019 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 export LC_ALL=C
 KNOWN_VIOLATIONS=(