lsp: Finishing last missing test wrt complex nested project directory structure and specifying custom includes, while using some (one) of them.

test/libsolidity/lsp/include-paths-nested-2/A/B/C/foo.sol

@@ -0,0 +1,8 @@
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity >=0.8.0;
+
+import "otherlib/second.sol";
+
+contract C
+{
+}

test/libsolidity/lsp/include-paths-nested-2/A/B/foo.sol

@@ -0,0 +1,6 @@
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity >=0.8.0;
+
+contract B
+{
+}

test/libsolidity/lsp/include-paths-nested-2/A/foo.sol

@@ -0,0 +1,6 @@
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity >=0.8.0;
+
+contract A
+{
+}

test/libsolidity/lsp/include-paths-nested-2/foo.sol

@@ -0,0 +1,6 @@
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity >=0.8.0;
+
+contract RootContract
+{
+}

test/libsolidity/lsp/other-include-dir/otherlib/second.sol

@@ -0,0 +1,7 @@
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity >=0.8.0;
+
+library Second
+{
+    function f(uint n) public pure returns (uint) { return n + 1; }
+}