MDEV-12858 + MDEV+12859 + MDEV-12862 - a join patch fixing a few data type problems with CREATE..SELECT

MDEV-12858 Out-of-range error for CREATE..SELECT unsigned_int_column+1
MDEV-12859 Out-of-range error for CREATE..SELECT @A:=EXTRACT(MINUTE_MICROSECOND FROM..)
MDEV-12862 Data type of @A:=1e0 depends on the session character set

1. Moving a part of Item::create_tmp_field() into a new helper method
   Item::create_tmp_field_int() and reusing it in Item::create_tmp_field()
   and Item_func_signed::create_tmp_field().
   Fixing the code in Item::create_tmp_field_int() to call
   Type_handler::make_table_field() instead of doing "new Field_long[long]"
   directly. This change revealed a problem reported in MDEV-12862.

2. Changing the "long vs longlong" cut-off length for
     - Item_func::create_tmp_field()
     - Item_sum::create_tmp_field()
     - Item_func_get_user_var::create_tmp_field()
   from MY_INT32_NUM_DECIMAL_DIGITS to (MY_INT32_NUM_DECIMAL_DIGITS - 2).
   This fixes MDEV-12858.
   After this change, the "convert_int_length" parameter to
   Item::create_tmp_field() is not needed any more, because
   (MY_INT32_NUM_DECIMAL_DIGITS - 2) is always passed.
   So removing the "convert_int_length" parameter.

3. Fixing Item::create_tmp_field() to pass max_char_length() instead
   of max_length to the constructor of Field_double().
   This fixes MDEV-12862.

4. Additionally, fixing
   - Type_handler_{tiny|short|int24|long|longlong}::make_table_field()
   - Type_handler_{float|double}::make_table_field()
   to pass max_char_length() instead of max_length to Field contructors.
   This is needed by the change (1).

5. Adding new tests, and recording new correct results in the old tests in:
   - mysql-test/r/type_ranges.result
   - storage/tokudb/mysql-test/tokudb/r/type_ranges.result