Fix Mod and Div precision/scale issues in ColumnStore (MCOL-4601)

[shivasavade]

1. Fix incorrect MOD calculation for DECIMAL operands in ColumnStore.
   Root Cause:
   • The divisor was truncated to an integer (div), losing its scale. May not work is the interger part is zero. (e.g: 0.5)
   • Modulus computation used integer arithmetic instead of scaled decimal arithmetic.
   • Precision and scale were not correctly aligned between the dividend and divisor.

Solution:
• Retrieve both operands as IDB_Decimal values using getDecimalVal().
• Normalize the scales of both operands using max(d.scale, div.scale).
• Perform modulus on properly scaled 128-bit integer representations.
• Return a result with consistent scale and divisor precision.

2. Fix incorrect DIV calculation for DECIMAL operands in ColumnStore.
   Root Cause:
   • Operands were converted to double, losing precision for DECIMAL values.
   • Scale differences between dividend and divisor were not handled.
   • Also, double cannot exactly represent 1.1 in binary.
   1.1 in base 10 equals:
   1 + 1/10 = 1 + 0.0001100110011001100...(in binary)
   That repeating binary fraction never ends.
   When stored in a finite 64-bit double, it gets rounded to the closest representable number, which is actually: 1.1000000000000001

Solution:
• For exact decimal display, Its better we use the DECIMAL, not double.
• When printing doubles, format to a fixed precision: 1.1000000000000001
• Retrieve operands as IDB_Decimal instead of double.
• Normalize scales between dividend (dec1) and divisor (dec2) before performing division.
• Use 128-bit integer arithmetic for precise scaled division.

[mariadb-LeonidFedorov]

Thank you for the contribution!
Could you please add the tests covering your fix columnstore/basic/t/mcs227_div_function.test
To run the test and to update the reference output columnstore/basic/r/mcs227_div_function.result, you can use
--record of following script

➜  sudo tests/scripts/run_mtr.sh --help
usage: tests/scripts/run_mtr.sh [OPTIONS]
OPTIONS:
        
	-s --suite:                  whole suite to run
	-t --test_full_name:         Testname with suite as like bugfixes.mcol-4899
	-f --full:                   Run full MTR [default:false]
	-r --record:                 Record the result [default:false]
	-e --no-extern:              Run with --extern [default:false]
	-c --color:                  run with unbufer to colorize output [default:false]
        -? --help  :  usage