1. Support modify column type CHAR to TINYINT/SMALLINT/INT/BIGINT/LARGEINT/FLOAT/DOUBLE/DATE
and TINYINT/SMALLINT/INT/BIGINT/LARGEINT/FLOAT/DOUBLE convert to a wider range of numeric types (#4937)
2. Use template to refactor code of types.h and schema_change.cpp to delete redundant code.
This PR is mainly do three things:
1. Fix fe meta version bug introduced by #4029 , when fix conflict with #4086
2. Make drop check code easy to read
3. Add doc content for drop meta check
[Bug]Fix some schema change not work right
This CL mainly fix some schema change to varchar type not work right
because forget to logic check && Add ConvertTypeResolver to add
supported convert type in order to avoid forget logic check