Add a --descriptors option to various tests

Adds a --descriptors option globally to the test framework. This will
make the test create and use descriptor wallets. However some tests may
not work with this.

Some tests are modified to work with --descriptors and run with that
option in test_runer:
* wallet_basic.py
* wallet_encryption.py
* wallet_keypool.py
* wallet_keypool_topup.py
* wallet_labels.py
* wallet_avoidreuse.py

test/functional/test_runner.py

@@ -76,6 +76,7 @@ BASE_SCRIPTS = [
     # Scripts that are run by default.
     # Longest test should go first, to favor running tests in parallel
     'wallet_hd.py',
+    'wallet_hd.py --descriptors',
     'wallet_backup.py',
     # vv Tests less than 5m vv
     'mining_getblocktemplate_longpoll.py',
@@ -86,7 +87,9 @@ BASE_SCRIPTS = [
     'feature_segwit.py',
     # vv Tests less than 2m vv
     'wallet_basic.py',
+    'wallet_basic.py --descriptors',
     'wallet_labels.py',
+    'wallet_labels.py --descriptors',
     'p2p_segwit.py',
     'p2p_timeouts.py',
     'p2p_tx_download.py',
@@ -109,6 +112,7 @@ BASE_SCRIPTS = [
     'feature_abortnode.py',
     # vv Tests less than 30s vv
     'wallet_keypool_topup.py',
+    'wallet_keypool_topup.py --descriptors',
     'feature_fee_estimation.py',
     'interface_zmq.py',
     'interface_bitcoin_cli.py',
@@ -122,6 +126,7 @@ BASE_SCRIPTS = [
     'interface_rest.py',
     'mempool_spend_coinbase.py',
     'wallet_avoidreuse.py',
+    'wallet_avoidreuse.py --descriptors',
     'mempool_reorg.py',
     'mempool_persist.py',
     'wallet_multiwallet.py',
@@ -134,6 +139,7 @@ BASE_SCRIPTS = [
     'interface_http.py',
     'interface_rpc.py',
     'rpc_psbt.py',
+    'rpc_psbt.py --descriptors',
     'rpc_users.py',
     'rpc_whitelist.py',
     'feature_proxy.py',
@@ -147,6 +153,7 @@ BASE_SCRIPTS = [
     'p2p_addr_relay.py',
     'rpc_net.py',
     'wallet_keypool.py',
+    'wallet_keypool.py --descriptors',
     'wallet_descriptor.py',
     'p2p_mempool.py',
     'p2p_filter.py',
@@ -169,6 +176,7 @@ BASE_SCRIPTS = [
     'mempool_packages.py',
     'mempool_package_onemore.py',
     'rpc_createmultisig.py',
+    'rpc_createmultisig.py --descriptors',
     'feature_versionbits_warning.py',
     'rpc_preciousblock.py',
     'wallet_importprunedfunds.py',
@@ -192,6 +200,7 @@ BASE_SCRIPTS = [
     'wallet_listsinceblock.py',
     'p2p_leak.py',
     'wallet_encryption.py',
+    'wallet_encryption.py --descriptors',
     'feature_dersig.py',
     'feature_cltv.py',
     'rpc_uptime.py',