private-vars-leading-underscore on internal functions in libraries is not a best practice

[ZumZoom]

In #511 a change was made to treat library internal functions the same way they are treated in contracts. Almost all of the solidity libraries are not using underscore for internal functions naming. Even in the official docs they don't use underscores on internal functions in libraries https://docs.soliditylang.org/en/latest/contracts.html#libraries.

[dbale-altoros]

@ZumZoom good catch
we will review this
thanks for the input!

[dbale-altoros]

Corrected here
#525