Merge bitcoin/bitcoin#30463: qa: Functional test improvements

a8e3af1a82dd584a1cc3ffbe587e66889f72e3c7 qa: Do not assume running `feature_asmap.py` from source directory (Hennadii Stepanov)
9bf7ca6cad888d460f57d249264dc0062025bb3f qa: Consider `cache` and `config.ini` relative to invocation directory (Hennadii Stepanov)
a0473442d1c22043f5a288bd9255c006fd85d947 scripted-diff: Add `__file__` argument to `BitcoinTestFramework.init()` (Hennadii Stepanov)

Pull request description:

  This PR includes changes split from https://github.com/bitcoin/bitcoin/pull/30454. They improve the functional test framework, allowing users to [run individual functional tests](https://github.com/hebasto/bitcoin/issues/146) from the build directory in the new CMake-based build system.

  This functionality is not available for out-of-source builds using the current Autotools-based build system, which always requires write permissions for the source directory. Nevertheless, this PR can be tested as suggested in https://github.com/bitcoin/bitcoin/pull/30463#issuecomment-2232618421:
  1. Make an out-of-source build:
  ```
  $ ./autogen.sh
  $ mkdir ../build && cd ../build
  $ ../bitcoin/configure
  $ make
  ```
  2. Create a symlink in the build directory to a functional test:
  ```
  $ ln --symbolic ../../../bitcoin/test/functional/wallet_disable.py ./test/functional/
  ```
  3. Run this symlink:
  ```
  $ ./test/functional/wallet_disable.py
  ```
  The last command fails on the master branch:
  ```
  Traceback (most recent call last):
    File "/home/hebasto/git/build/./test/functional/wallet_disable.py", line 31, in <module>
      DisableWalletTest().main()
      ^^^^^^^^^^^^^^^^^^^
    File "/home/hebasto/git/bitcoin/test/functional/test_framework/test_framework.py", line 106, in __init__
      self.parse_args()
    File "/home/hebasto/git/bitcoin/test/functional/test_framework/test_framework.py", line 210, in parse_args
      config.read_file(open(self.options.configfile))
                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  FileNotFoundError: [Errno 2] No such file or directory: '/home/hebasto/git/bitcoin/test/config.ini'

  ```
  and succeeds with this PR.

ACKs for top commit:
  maflcko:
    tested ACK a8e3af1a82dd584a1cc3ffbe587e66889f72e3c 🎨
  glozow:
    ACK a8e3af1a82dd584a1cc3ffbe587e66889f72e3c7, tested with the steps in op
  stickies-v:
    ACK a8e3af1a82dd584a1cc3ffbe587e66889f72e3c7

Tree-SHA512: 899e4efc09edec13ea3f5b47825d03173fb21d3569c360deda7fa6a56b99b4d24e09ad4f0883bad1ee926b1c706e47ba07c6a6160c63c07c82b3cf4ae5816e91

1 files changed, 1 insertions, 1 deletions

diff --git a/test/functional/p2p_add_connections.py b/test/functional/p2p_add_connections.py
index 0775fd873d..ee0cbdfa19 100755
--- a/test/functional/p2p_add_connections.py
+++ b/test/functional/p2p_add_connections.py
@@ -129,4 +129,4 @@ class P2PAddConnections(BitcoinTestFramework):
 
 
 if __name__ == '__main__':
-    P2PAddConnections().main()
+    P2PAddConnections(__file__).main()