More refactoring of tests and packages

Squashed commit of the following:

commit c4659d8be4d664ba7fd4b59d613536f2368cff0e
Author: riton <riton@riton.home>
Date:   Mon Jul 14 21:44:48 2025 +0300

    fix package name typo

commit ec802339b838d059f4bc9e4da7cc370ab4d91a46
Author: riton <riton@riton.home>
Date:   Mon Jul 14 21:43:42 2025 +0300

    seperate deftest from test instances

commit 92d20e0b8405a4a51f01ff65f8bd81f4d25c1e21
Author: riton <riton@riton.home>
Date:   Mon Jul 14 21:29:47 2025 +0300

    make a test system definition

commit 125e5fe1e8c07230f32e762273c5c0dd259209e6
Author: riton <riton@riton.home>
Date:   Mon Jul 14 00:39:09 2025 +0300

    compiler macro of as-token

commit 0e39c32097783aa39e3fed479bb85b412065f597
Author: riton <riton@riton.home>
Date:   Mon Jul 14 00:21:46 2025 +0300

    define new packages

1 files changed, 9 insertions, 1 deletions

diff --git a/monkey.asd b/monkey.asd
index b885b76..80ff674 100644
--- a/monkey.asd
+++ b/monkey.asd
@@ -8,4 +8,12 @@
                (:file "token")
                (:file "lexer")
                ;; (:file "parser")
-               ))
+               )
+  :in-order-to ((test-op (test-op "monkey/test"))))
+
+(defsystem "monkey/test"
+  :depends-on ("monkey")
+  :pathname "test/"
+  :components ((:file "tester")
+               (:file "lexer-test"))
+  :perform (test-op (o c) (symbol-call :monkey/test :run-tests)))