PR into master from dev/olga/Fixed-spaces-for-operatorname-in-asciimath

[OlgaRedozubova]

branch: dev/olga/Fixed-spaces-for-operatorname-in-asciimath

Why:

• Improved conversion to asciimath for operatorname

What's being changed:

latex: a \operatorname { \lambda mod } b ascimath: a lambda mod b instead of alambda modb

latex: a \operatorname{m} b ascimath: a m b instead of amb

Fixed:

latex: i \oint ascimath: i oint instead of ioint