[SETUPLIB][REACTOS][USETUP] Turn setuplib into a DLL shared between TUI and GUI 1st-stage setups (#7523)

CORE-13525

Notes:
- Most of the exported functions have been turned from default cdecl to explicit stdcall / "NTAPI".
- The two InitializeSetup() phases have been collapsed to make the initialization simpler.

Average reductions (percentages; see PR #7523 for actual numbers):

x86 Debug builds:
reactos.exe: 35.1%
smss.exe   : 39.8%
Total (including setuplib.dll): 17.9%

x86 Release builds:
reactos.exe: 22.3%
smss.exe   : 25.0%
Total (including setuplib.dll): 10.6%

x64 Debug builds:
reactos.exe: 40.6%
smss.exe   : 41.6%
Total (including setuplib.dll): 20.0%

x64 Release builds:
reactos.exe: 22.8%
smss.exe   : 22.3%
Total (including setuplib.dll): 10.1%

base/setup/lib/utils/genlist.h

@@ -24,37 +24,45 @@ typedef struct _GENERIC_LIST
 
 
 PGENERIC_LIST
+NTAPI
 CreateGenericList(VOID);
 
 VOID
+NTAPI
 DestroyGenericList(
     IN OUT PGENERIC_LIST List,
     IN BOOLEAN FreeData);
 
 BOOLEAN
+NTAPI
 AppendGenericListEntry(
     IN OUT PGENERIC_LIST List,
     IN PVOID Data,
     IN BOOLEAN Current);
 
 VOID
+NTAPI
 SetCurrentListEntry(
     IN PGENERIC_LIST List,
     IN PGENERIC_LIST_ENTRY Entry);
 
 PGENERIC_LIST_ENTRY
+NTAPI
 GetCurrentListEntry(
     IN PGENERIC_LIST List);
 
 PGENERIC_LIST_ENTRY
+NTAPI
 GetFirstListEntry(
     IN PGENERIC_LIST List);
 
 PGENERIC_LIST_ENTRY
+NTAPI
 GetNextListEntry(
     IN PGENERIC_LIST_ENTRY Entry);
 
 PVOID
+NTAPI
 GetListEntryData(
     IN PGENERIC_LIST_ENTRY Entry);
 
@@ -63,6 +71,7 @@ GetListEntryUiData(
     IN PGENERIC_LIST_ENTRY Entry);
 
 ULONG
+NTAPI
 GetNumberOfListEntries(
     IN PGENERIC_LIST List);