Migrating the `Util.kt` and `KModifier` from JVM to common

[ForteScarlet]

Part of #304, #1959

Migrating Util.kt and KModifier from JVM to common.

• Non-JVM platform implementations have some questionable implementations (They mark the TODO).
• There is a known issue (KT-71003) regarding the use of Kotlin Regex in WasmJS.
• there are some functions that need to wait for other types of migration.

On the JVM, however, the effect is the same before and after migration.

Let me know if there's anything I need to do, thanks. If these changes are not reviewed until after 2.0, you can always tell me, convert it to draft, or close it~