When projecting, use GetName instead of ToString()

- Merge pull request duckdb/duckdb#8717 from Tmonster/projection_quoted_columns

- Indent tests, was part of of the following PRs which otherwise cancel themselves out:

- Merge pull request duckdb/duckdb#8600 from krlmlr/b-altrep-unwind: R: Fix core dump when failing to evaluate ALTREP query

- Merge pull request duckdb/duckdb#8647 from krlmlr/b-altrep-cpp11-wrap: Wrap ALTREP methods with BEGIN_CPP11 and END_CPP11

- Merge pull request duckdb/duckdb#8207 from krlmlr/b-copy-string: R: Avoid crash when finalizing

- Merge pull request duckdb/duckdb#8272 from krlmlr/b-warn-copy: Remove dangerous overload of cpp11::warning()

Author: hannes

src/relational.cpp

@@ -172,7 +172,7 @@ external_pointer<T> make_external_prot(const string &rclass, SEXP prot, ARGS &&.
 
 	for (expr_extptr_t expr : exprs) {
 		auto dexpr = expr->Copy();
-		aliases.push_back(dexpr->alias.empty() ? dexpr->ToString() : dexpr->alias);
+		aliases.push_back(dexpr->GetName());
 		projections.push_back(std::move(dexpr));
 	}