Remove the last ConfigEntry state (#1902)

* Get rid of `ConfigEntry::ExternalBIOSEnable`

- Now the BIOS files themselves are checked
- The frontend's `Config::ExternalBIOSEnable` is not affected

* Add `JITArgs`

* Pass the JIT status to the `ARM` constructors

* Encapsulate `NDS::EnableJIT`

* Pass `JITArgs` to `ARMJIT`'s constructor

* Remove the `JIT_*` `ConfigEntry`s in favor of members

- Allow all the JIT args to be set with `NDS::SetJITArgs`
- Encapsulate the JIT-related parameters in `ARMJIT` so they can reset the block cache if changed
- Update the active (or newly-created) console in the frontend with adjusted JIT args

* Make audio bit depth and interpolation configurable in `NDSArgs`

- Define enums for both
- Give those settings default values in `NDSArgs`
- Remove `ConfigEntry::AudioBitDepth`
- Initialize these settings in the relevant SPU constructors

* Move the last DSi-specific logic in `Reset` to its own subclass

* Remove `ConfigEntry::DSi_FullBIOSBoot`

- Add members to `DSi` instead for getting and setting this
- Update the frontend to accommodate these changes

* Oops, missed a spot

* Remove `ConfigEntry::Firm_MAC` and `Platform::GetConfigArray`

- Also move the MAC parsing code to `ROMManager`

* Remove the last `ConfigEntry` state

- Make GDB support configurable via members

* Add some `#ifdef`s that I'd almost forgotten

src/NDS.h

@@ -219,11 +219,12 @@ class ARMJIT;
 
 class NDS
 {
-public:
-
+private:
 #ifdef JIT_ENABLED
     bool EnableJIT;
 #endif
+
+public:
     int ConsoleType;
     int CurCPU;
 
@@ -433,6 +434,11 @@ public:
     virtual void ARM7IOWrite16(u32 addr, u16 val);
     virtual void ARM7IOWrite32(u32 addr, u32 val);
 
+#ifdef JIT_ENABLED
+    [[nodiscard]] bool IsJITEnabled() const noexcept { return EnableJIT; }
+    void SetJITArgs(std::optional<JITArgs> args) noexcept;
+#endif
+
 private:
     void InitTimings();
     u32 SchedListMask;