feat(shell): support resolve IP address in dsn/utility

[Smityz]

What problem does this PR solve?

• Return original IP address if resolve failed
• Move util functions into dsn/utility

What is changed and how it works?

// valid a.b.c.d：port -> return TRUE && hostname_result=hostname:port
// | invalid a.b.c.d:port1-> return FALSE  && hostname_result=a.b.c.d:port
bool hostname_from_ip_port(const char *ip_port, std::string *hostname_result);

Check List

Tests

• Unit test
  I add a unit test in /src/core/tests/hostname.cpp
• Integration test
• Manual test (add detailed scripts or steps below)
• No code

Code changes

• Has exported function/method change
• Has exported variable/fields change
• Has interface methods change
• Has persistent data change

Side effects

• Possible performance regression
• Increased code complexity
• Breaking backward compatibility

Related changes

• Need to cherry-pick to the release branch
• Need to update the documentation
• Need to be included in the release note

[vagetablechicken]

👏

[neverchanje]

为什么不直接写一个新文件 hostname_utils.h/hostname_utils.cpp 啊，utils.h 里的东西太杂了，很难管理

[neverchanje]

同上，建议改名 hostname_utils_test.cpp