scripted-diff: use insecure_rand256/randrange more

-BEGIN VERIFY SCRIPT-
sed -i "s/\<GetRandHash(/insecure_rand256(/" src/test/*_tests.cpp
sed -i "s/\<GetRand(/insecure_randrange(/" src/test/*_tests.cpp src/test/test_bitcoin.cpp
sed -i 's/\<insecure_rand() % \([0-9]\+\)/insecure_randrange(\1)/g' src/test/*_tests.cpp
-END VERIFY SCRIPT-

src/test/bloom_tests.cpp

@@ -463,7 +463,7 @@ BOOST_AUTO_TEST_CASE(merkle_block_4_test_update_none)
 
 static std::vector<unsigned char> RandomData()
 {
-    uint256 r = GetRandHash();
+    uint256 r = insecure_rand256();
     return std::vector<unsigned char>(r.begin(), r.end());
 }