This adds the following functions to cmStringAlgorithms:
- `cmIsInternallyOn`
- `cmIsNOTFOUND`
- `cmIsOn`
- `cmIsOff`
The implementations were copied from the equivalent functions in cmSystemTools.
This adds the following functions to cmStringAlgorithms:
- `cmStrToLong`: moved from `cmSystemTools::StringToLong`
- `cmStrToULong`: moved from `cmSystemTools::StringToULong`
Overloads of the given functions for `std::string` are added as well.
This adds the following functions to `cmStringAlgorithms`:
- `cmIsSpace`
- `cmTrimWhitespace` (moved from `cmSystemTools::TrimWhitespace`)
- `cmEscapeQuotes` (moved from `cmSystemTools::EscapeQuotes`)
- `cmTokenize` (moved from `cmSystemTools::tokenize` and adapted to
accept `cm::string_view`)