Remove the functionality to define a pattern to determine the project
name and instead make the project name configurable as a constant value,
because in practice it turned out that the flexibility provided by the
pattern is not required.

If no `projectName` is configured, it is determined from the Git
repository URL as before.

This change requires adaptations in the "delete newly triggered scans
if a package cannot be scanned" test, because it used mocking to make
the removed `createProjectCode` function behave in a way it would not
behave at runtime.

Signed-off-by: Martin Nonnenmacher <[email protected]>

Add support for `projectName` as a built-in variable for the
`namingScanPattern`. This allows to easily include the project name in
the generated scan code.

Signed-off-by: Martin Nonnenmacher <[email protected]>

Remove support for adding custom naming variables prefixed with
`namingVariable`. Instead, custom values can be written directly into
the `namingScanPattern`.

Signed-off-by: Martin Nonnenmacher <[email protected]>

Replace the custom options to define URL mappings with a single
comma-separated option `urlMappings`. This will simplify the migration
to the new plugin API.

Signed-off-by: Martin Nonnenmacher <[email protected]>

This allows handling the property like all other config properties for
consistency and removes the need to store the plain `options` in the
config class.

Signed-off-by: Martin Nonnenmacher <[email protected]>