Remove unused logo file from "Hello OpenAssetIO" notebook

[feltech]

Closes #85. The logo file in the hello_openassetio resources directory was the deliberately misspelled logo from the querying_entity_versions notebook. Also, the logo file itself is never used within the notebook.

So remove the logo file, and use an obvious dummy path to the logo for exemplification purposes instead.

[elliotcmorris]

Path is relative errors on the new URL in tests. ... I wonder if we can be more descriptive about this, I got it a lot doing the BAL work and it's hard for the layperson to understand what about the path makes it relative, as it's often to do with the leading slashes.

[feltech]

Path is relative errors on the new URL in tests. ... I wonder if we can be more descriptive about this, I got it a lot doing the BAL work and it's hard for the layperson to understand what about the path makes it relative, as it's often to do with the leading slashes.

It's tricky to find a URL/path that works cross-platform. file:///c:/path actually works on both platforms, but /c:/path doesn't "look right" on POSIX. So now I've (force-) pushed an update that pins to PathType.kPOSIX.

There are a few places where we could be more specific about the reason for it being parsed as a relative path (see usages of kErrorRelativePath). Would involve updating every test in the massive test database, though, so it's not a 2 min change.