[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/fsutil.h

@@ -12,6 +12,7 @@
 
 /** QueryAvailableFileSystemFormat() **/
 BOOLEAN
+NTAPI
 GetRegisteredFileSystems(
     IN ULONG Index,
     OUT PCWSTR* FileSystemName);
@@ -19,6 +20,7 @@ GetRegisteredFileSystems(
 
 /** ChkdskEx() **/
 NTSTATUS
+NTAPI
 ChkdskFileSystem_UStr(
     _In_ PUNICODE_STRING DriveRoot,
     _In_ PCWSTR FileSystemName,
@@ -29,6 +31,7 @@ ChkdskFileSystem_UStr(
     _In_opt_ PFMIFSCALLBACK Callback);
 
 NTSTATUS
+NTAPI
 ChkdskFileSystem(
     _In_ PCWSTR DriveRoot,
     _In_ PCWSTR FileSystemName,
@@ -41,6 +44,7 @@ ChkdskFileSystem(
 
 /** FormatEx() **/
 NTSTATUS
+NTAPI
 FormatFileSystem_UStr(
     _In_ PUNICODE_STRING DriveRoot,
     _In_ PCWSTR FileSystemName,
@@ -51,6 +55,7 @@ FormatFileSystem_UStr(
     _In_opt_ PFMIFSCALLBACK Callback);
 
 NTSTATUS
+NTAPI
 FormatFileSystem(
     _In_ PCWSTR DriveRoot,
     _In_ PCWSTR FileSystemName,
@@ -109,6 +114,7 @@ InstallNtfsBootCode(
 //
 
 NTSTATUS
+NTAPI
 ChkdskPartition(
     _In_ PPARTENTRY PartEntry,
     _In_ BOOLEAN FixErrors,
@@ -118,6 +124,7 @@ ChkdskPartition(
     _In_opt_ PFMIFSCALLBACK Callback);
 
 NTSTATUS
+NTAPI
 FormatPartition(
     _In_ PPARTENTRY PartEntry,
     _In_ PCWSTR FileSystemName,
@@ -200,6 +207,7 @@ typedef FSVOL_OP
     _In_ ULONG_PTR Param2);
 
 BOOLEAN
+NTAPI
 FsVolCommitOpsQueue(
     _In_ PPARTLIST PartitionList,
     _In_ PVOLENTRY SystemVolume,