feat(3p/lisp): Add str package and dependencies

Change-Id: Iffb66f4580517b1dbfee8c79e766552508695e5f
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11252
Reviewed-by: sterni <sternenseemann@systemli.org>
Tested-by: BuildkiteCI
Autosubmit: aspen <root@gws.fyi>

third_party/lisp/cl-change-case.nix

@@ -0,0 +1,22 @@
+{ depot, pkgs, ... }:
+
+let src = with pkgs; srcOnly lispPackages.cl-change-case;
+in depot.nix.buildLisp.library {
+  name = "cl-change-case";
+
+  deps = with depot.third_party.lisp; [ cl-ppcre cl-ppcre.unicode ];
+
+  srcs = [ (src + "/src/cl-change-case.lisp") ];
+
+  tests = {
+    name = "cl-change-case-tests";
+    srcs = [ (src + "/t/cl-change-case.lisp") ];
+    deps = [
+      depot.third_party.lisp.fiveam
+    ];
+
+    expression = ''
+      (5am:run! :cl-change-case)
+    '';
+  };
+}