Add support for function mod (#2402)

[ti-srebot]

cherry-pick #2402 to release-5.0
You can switch your code base to this Pull Request by using git-extras:

# In tics repo:
git pr https://github.com/pingcap/tics/pull/2561

After apply modifications, you can push your change to this PR via:

git push git@github.com:ti-srebot/tics.git pr/2561:release-5.0-685880a29558

---

What problem does this PR solve?

Issue Number: close #2318

Problem Summary: enable pushing function mod down to TiFlash.

What is changed and how it works?

Proposal:

What's Changed:

• Decimal.h: compatible with TiDB.
• DataTypeDecimal.h: add a helper function to get decimal precision in unit test.
• DAGUtils.cpp: add mappings from TiPB codes to scalar function name.
• FunctionArithmetic.h: update implementation of FunctionModulo.
• NumberTraits.h: fix modulo result type deduction.
• types.h: add actual_type, which returns correct size of boost multiprecision integer.
• mod.test, mod_extra.test: the integration test.
• gtest_arithmetic_functions.cpp: the unit test.

Related changes

• PR to update pingcap/docs/pingcap/docs-cn:
• Need to cherry-pick to the release branch:

Check List

• Examine current implementation
  • Return type detection
  • Decimal precision and scale
  • Floating point: INF, NaN
• Fix compiler warnings

Tests

• Unit test
• Integration test

Release note

• Support pushing down MOD(N, M) to TiFlash.

[windtalker]

close as it is not needed in 5.0.x