[common] Switch to boost::unordered_flat containers (#4326)

Replaces all instances of ankerl's unordered map/set with boost's
`unordered_flat_*` classes. This uses std::hash since boost::hash is
actually a lot slower.

Also adds an abstraction layer in `Common` so future changes are quicker
and easier.

Other implementation details:
- ankerl provided hash specializations for tuple and pair, so those were
  ported here
- std::erase_if doesn't work on boost, so just used the ADL'd erase_if

This should be about equal or superior performance as unordered_dense for everything except iteration.

Signed-off-by: crueter <crueter@eden-emu.dev>

- [x] I have read and followed the [Contribution Guidelines](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/CONTRIBUTING.md#code-contributions).
- [x] I have read and followed the [AI Policy](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/docs/policies/AI.md)
- [x] I have read and followed the [Coding Guidelines](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/docs/policies/Coding.md) to the best of my ability.

-------------------

Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/4326
Reviewed-by: Lizzie and Samuel <lizzie@eden-emu.dev>
Reviewed-by: MaranBr <maranbr@eden-emu.dev>

src/core/file_sys/ips_layer.cpp

@@ -8,7 +8,7 @@
 #include <utility>
 #include <span>
 #include <cctype>
-#include <ankerl/unordered_dense.h>
+#include "common/container/unordered_map.h"
 
 #include "common/hex_util.h"
 #include "common/logging.h"
@@ -104,7 +104,7 @@ struct IPSwitchRecord {
     size_t count;
 };
 struct IPSwitchCompiler::IPSwitchPatch {
-    ankerl::unordered_dense::map<u32, IPSwitchRecord> records;
+    ::Common::unordered_map<u32, IPSwitchRecord> records;
     bool enabled;
 };
 

src/core/file_sys/registered_cache.cpp

@@ -566,7 +566,7 @@ VirtualFile RegisteredCache::GetFileAtID(NcaID id) const {
     return file;
 }
 
-static std::optional<NcaID> CheckMapForContentRecord(const ankerl::unordered_dense::map<u64, CNMT>& map, u64 title_id, ContentRecordType type) {
+static std::optional<NcaID> CheckMapForContentRecord(const ::Common::unordered_map<u64, CNMT>& map, u64 title_id, ContentRecordType type) {
     auto cmnt_iter = map.find(title_id);
     u8 id_offset = 0;
 

src/core/file_sys/registered_cache.h

@@ -12,7 +12,7 @@
 #include <optional>
 #include <string>
 #include <vector>
-#include <ankerl/unordered_dense.h>
+#include "common/container/unordered_map.h"
 #include <boost/container/flat_map.hpp>
 #include "common/common_types.h"
 #include "core/crypto/key_manager.h"
@@ -209,11 +209,11 @@ private:
     ContentProviderParsingFunction parser;
 
     // maps tid -> NcaID of meta
-    ankerl::unordered_dense::map<u64, NcaID> meta_id;
+    ::Common::unordered_map<u64, NcaID> meta_id;
     // maps tid -> meta
-    ankerl::unordered_dense::map<u64, CNMT> meta;
+    ::Common::unordered_map<u64, CNMT> meta;
     // maps tid -> meta for CNMT in yuzu_meta
-    ankerl::unordered_dense::map<u64, CNMT> yuzu_meta;
+    ::Common::unordered_map<u64, CNMT> yuzu_meta;
 };
 
 enum class ContentProviderUnionSlot {
@@ -313,8 +313,8 @@ private:
     void ProcessXCI(const VirtualFile& file);
 
     std::vector<VirtualDir> load_dirs;
-    ankerl::unordered_dense::map<std::tuple<u64, ContentRecordType, TitleType>, VirtualFile> entries;
-    ankerl::unordered_dense::map<u64, u32> versions;
+    ::Common::unordered_map<std::tuple<u64, ContentRecordType, TitleType>, VirtualFile> entries;
+    ::Common::unordered_map<u64, u32> versions;
     std::vector<ExternalUpdateEntry> multi_version_entries;
 };
 

src/core/file_sys/vfs/vfs_layered.cpp

@@ -6,7 +6,7 @@
 
 #include <algorithm>
 #include <set>
-#include <ankerl/unordered_dense.h>
+#include "common/container/unordered_set.h"
 #include <utility>
 #include "core/file_sys/vfs/vfs_layered.h"
 
@@ -63,7 +63,7 @@ std::string LayeredVfsDirectory::GetFullPath() const {
 
 std::vector<VirtualFile> LayeredVfsDirectory::GetFiles() const {
     std::vector<VirtualFile> out;
-    ankerl::unordered_dense::set<std::string> out_names;
+    ::Common::unordered_set<std::string> out_names;
 
     for (const auto& layer : dirs) {
         for (auto& file : layer->GetFiles()) {
@@ -79,7 +79,7 @@ std::vector<VirtualFile> LayeredVfsDirectory::GetFiles() const {
 
 std::vector<VirtualDir> LayeredVfsDirectory::GetSubdirectories() const {
     std::vector<VirtualDir> out;
-    ankerl::unordered_dense::set<std::string> out_names;
+    ::Common::unordered_set<std::string> out_names;
 
     for (const auto& layer : dirs) {
         for (const auto& sd : layer->GetSubdirectories()) {