ACL: Add projects to team should only show not yet added projects

[rkg-mm]

Description

ACL: Add projects to team should only show not yet added projects
Required for Frontend PR: DependencyTrack/frontend#662

Addressed Issue

DependencyTrack/frontend#101

Additional Details

Checklist

• I have read and understand the contributing guidelines
• This PR fixes a defect, and I have provided tests to verify that the fix is effective
• This PR implements an enhancement, and I have provided tests to verify that it works as intended
• This PR introduces changes to the database model, and I have added corresponding update logic
• This PR introduces new or alters existing behavior, and I have updated the documentation accordingly

[nscuro]

Could this be added to the /api/v1/project endpoint instead? We already have a few query parameters there that allow for filtering of results:

dependency-track/src/main/java/org/dependencytrack/resources/v1/ProjectResource.java

Lines 88 to 98 in 2f16cae

	public Response getProjects(@ApiParam(value = "The optional name of the project to query on", required = false)
	@QueryParam("name") String name,
	@ApiParam(value = "Optionally excludes inactive projects from being returned", required = false)
	@QueryParam("excludeInactive") boolean excludeInactive,
	@ApiParam(value = "Optionally excludes children projects from being returned", required = false)
	@QueryParam("onlyRoot") boolean onlyRoot) {
	try (QueryManager qm = new QueryManager(getAlpineRequest())) {
	final PaginatedResult result = (name != null) ? qm.getProjects(name, excludeInactive, onlyRoot) : qm.getProjects(true, excludeInactive, onlyRoot);
	return Response.ok(result.getObjects()).header(TOTAL_COUNT_HEADER, result.getTotal()).build();
	}
	}

[rkg-mm]

you are right, makes sense. Done