feat: Add new operators.

[python-processing-unit]

Add the following new operators:

• IADD(INT|FLT: a, INT|FLT: b):INT ; Convert a and b to INT, return a + b.

• ISUB(INT|FLT: a, INT|FLT: b):INT ; Convert a and b to INT, return a - b.

• IMUL(INT|FLT: a, INT|FLT: b):INT ; Convert a and b to INT, return a * b.

• IDIV(INT|FLT: a, INT|FLT: b):INT ; Convert a and b to INT, return a / b.

• IPOW(INT|FLT: a, INT|FLT: b):INT ; Convert a and b to INT, return a ^ b.

• IROOT(INT|FLT: a, INT|FLT: b):INT ; Convert a and b to INT, return bth root of a.

• ISUM(INT|FLT: a1, ..., INT|FLT: aN):INT ; Convert all arguments to INT, return the sum of arguments.

• IPROD(INT|FLT: a1, ..., INT|FLT: aN):INT ; Convert a and b to INT, return the product of the arguments.

• FADD(INT|FLT: a, INT|FLT: b):FLT ; Convert a and b to FLT, return a + b.

• FSUB(INT|FLT: a, INT|FLT: b):FLT ; Convert a and b to FLT, return a - b.

• FMUL(INT|FLT: a, INT|FLT: b):FLT ; Convert a and b to FLT, return a * b.

• FDIV(INT|FLT: a, INT|FLT: b):FLT ; Convert a and b to FLT, return a / b.

• FPOW(INT|FLT: a, INT|FLT: b):FLT ; Convert a and b to FLT, return a ^ b.

• FROOT(INT|FLT: a, INT|FLT: b):FLT ; Convert a and b to FLT, return bth root of a.

• FSUM(INT|FLT: a1, ..., INT|FLT: aN):FLT ; Convert all arguments to FLT, return the sum of arguments.

• FPROD(INT|FLT: a1, ..., INT|FLT: aN):FLT ; Convert all arguments to FLT, return the product of arguments.