This opens path to per-reporter colour output customization,
and fixes multiple issues with the old colour implementation.
Under the old implementation, using Win32-backed colouring
would always change the colour used by the console, even if the
actual output was written elsewhere, such as a file passed by
the `--out` flag. This will no longer happen, as the reporter's
colour impl will check that the reporter's stream is pointed
to console before trying to change the colours.
POSIX/ANSI colour implementation suffered a similar-ish issue,
in that it only wrote the colour escape codes into the default
output stream, even if the reporter asking for colouring was
actually writing to a completely different output stream.
This will become useful when reworking colour support, because
Win32 colour support requires checking whether the output is
stdout, which is done through the `IStream` wrapper.
The problem came from the console reporter trying to provide a
fancy linebreaking (primarily for things like `SCENARIO` or the
BDD macros), so that new lines start with extra indentation if
the text being line broken starts as "{text}: ".
The console reporter did not properly take into account cases
where the ": " part would already be in a later line, in which
case it would ask for non-sensical level of indentation (larger
than single line length).
We fixed this by also enforcing that the special indentation case
only triggers if the ": " is found early enough in the line, so
that we also avoid degenerate cases like this:
```
blablabla: F
a
n
c
y
.
.
.
```
Fixes#2309
The problem with the old name was that it collided with the
range matcher `Contains`, and it was not really possible to
disambiguate them just with argument types.
Closes#2131
Martin Hořeňovský