refactor: modernize CScriptBase definition

Author: l0rinc

src/script/script.h

@@ -406,7 +406,7 @@ class CScriptNum
  * Tests in October 2015 showed use of this reduced dbcache memory usage by 23%
  *  and made an initial sync 13% faster.
  */
-typedef prevector<28, unsigned char> CScriptBase;
+using CScriptBase = prevector<28, uint8_t>;
 
 bool GetScriptOp(CScriptBase::const_iterator& pc, CScriptBase::const_iterator end, opcodetype& opcodeRet, std::vector<unsigned char>* pvchRet);