kernel: expose umount list to ioctl interface (#2950)

This idea is borrowed from simonpunk's susfs4ksu.
What we see here is that, yeah well, lets just have userspace send us
what it
wants unmounted, this is better than hardcoding everything.

This also solves that issue where MNT_DETACH fails, as long as we send
unmountables in proper order.

A small anti-duplicate mechanism is also added.

While in-kernel umount is a bit worse than zygisk-provider-based ones,
this can still
serve as a healthy alternative.

---------

- Remove duplicate checks

Signed-off-by: backslashxx <118538522+backslashxx@users.noreply.github.com>
Co-authored-by: weishu <twsxtd@gmail.com>
Co-authored-by: ShirkNeko <109797057+ShirkNeko@users.noreply.github.com>

manager/app/src/main/res/values-hi/strings.xml

@@ -124,7 +124,6 @@
     <string name="selected_lkm">Selected LKM: %s</string>
     <string name="save_log">लॉग सहेजें</string>
     <string name="log_saved">Logs saved</string>
-    <string name="sus_su_mode">SuS SU mode:</string>
     <!-- Module related -->
     <string name="module_install_confirm">confirm install module %1$s？</string>
     <string name="unknown_module">unknown module</string>
@@ -274,8 +273,6 @@
     <string name="advanced_settings">Advanced Settings</string>
     <string name="appearance_settings">Customize the toolbar</string>
     <string name="back">Comeback</string>
-    <string name="susfs_enabled">SuSFS enabled</string>
-    <string name="susfs_disabled">SuSFS disabled</string>
     <string name="background_set_success">Background set successfully</string>
     <string name="background_removed">Removed custom backgrounds</string>
     <string name="icon_switch_title">Alternate icon</string>