refactor argument system

- arguments can have multiple names simultaneously
- argument values can be passed using spaces (e.g., --arg value)
- single-character arguments can be passed using a single dash (e.g., --a -> -a)
- multiple single-character arguments can be combined (e.g., -a -b -> -ab)
- simplify custom arguments using generic classes

src/commonMain/kotlin/com/infendro/cli/util/Regex.kt

@@ -1,7 +1,6 @@
 package com.infendro.cli.util
 
 internal object Regex {
-    val COMMAND_NAME = """[a-z]+(?:-[a-z]+)*""".toRegex()
-    val ARGUMENT_NAME = """[a-z]+(?:[\-.][a-z]+)*""".toRegex()
-    val ARGUMENT = """--(?<name>[a-z]+(?:[\-.][a-z]+)*)(?:=(?<value>.*))?""".toRegex()
+    val COMMAND_NAME = Regex("""[a-z]+(?:-[a-z]+)*""")
+    val ARGUMENT_NAME = Regex("""[a-z]+(?:[\-.][a-z]+)*""")
 }