Merge #12895: tests: Add note about test suite name uniqueness requirement to developer notes

d1b622b tests: Add check for test suite name uniqueness in lint-tests.sh (practicalswift)
dc8067b tests: Add note about uniqueness requirement for test suite names (practicalswift)
3ebfb2d tests: Avoid test suite name collision in wallet crypto_tests (MarcoFalke)

Pull request description:

  * Add documentation: Add note about test suite name uniqueness requirement in developer notes
  * Add regression test: Update `lint-tests.sh` to make it check also for test suite name uniqueness

  Context: #12894 (`tests: Avoid test suite name collision in wallet crypto_tests`)

Tree-SHA512: 3c8502db069ef3d753f534976a86a997b12bac539e808a7285193bf81c9dd8c1b06821c3dd1bdf870ab87722b02c8aa9574c62ace70c2a1b8091785cb8c9aace

src/Makefile.test.include

@@ -94,7 +94,7 @@ BITCOIN_TESTS += \
   wallet/test/wallet_test_fixture.h \
   wallet/test/accounting_tests.cpp \
   wallet/test/wallet_tests.cpp \
-  wallet/test/crypto_tests.cpp \
+  wallet/test/wallet_crypto_tests.cpp \
   wallet/test/coinselector_tests.cpp
 endif
 

src/wallet/crypter.h

@@ -67,7 +67,7 @@ public:
 
 typedef std::vector<unsigned char, secure_allocator<unsigned char> > CKeyingMaterial;
 
-namespace crypto_tests
+namespace wallet_crypto_tests
 {
     class TestCrypter;
 }
@@ -75,7 +75,7 @@ namespace crypto_tests
 /** Encryption/decryption context with key information */
 class CCrypter
 {
-friend class crypto_tests::TestCrypter; // for test access to chKey/chIV
+friend class wallet_crypto_tests::TestCrypter; // for test access to chKey/chIV
 private:
     std::vector<unsigned char, secure_allocator<unsigned char>> vchKey;
     std::vector<unsigned char, secure_allocator<unsigned char>> vchIV;

src/wallet/test/wallet_crypto_tests.cpp

@@ -10,7 +10,7 @@
 
 #include <boost/test/unit_test.hpp>
 
-BOOST_FIXTURE_TEST_SUITE(crypto_tests, BasicTestingSetup)
+BOOST_FIXTURE_TEST_SUITE(wallet_crypto_tests, BasicTestingSetup)
 
 class TestCrypter
 {