Add numeric check on unary plus and unary minus

[VincentLanglet]

The operation $a + $b and $a - $b were checked but it was mising for the unary usage of these operators +$a or -$a.

Then, I plan to add such check for bitwise operators:

• & (AND)
• | (OR)
• << (Left shift)
• >> (Right shift)
• ^ (XOR)

I assume it should be behind a new config option numericOperandsInBitwiseOperators @ondrejmirtes ?

[ondrejmirtes]

Nice, thank you!