Try and preserve the wideness of std::filesystem::path more (#660)

As noted in #567, a filesystem path that contains non-ascii will break a
lot if using a clang toolchain.

Luckily, fmtlib has a lossy utf8 convert when you use it to print a path
(after including `fmt/std.h`). The vast majority of this diff is just
removing `.string()` from paths inside loggings calls.

There are some callsites I _didn't_ touch, mainly the options, because
it would be an ABI break to change those to be wide strings and I cbf
looking into settings upgrades. There are also some spots (avs mountpath
remapping, for example) where the path is guaranteed to be ascii, so I
didn't modify them.

ImGui doesn't appear to easily support wide strings (I mean, surely it
does, but I'm not gonna look too far into it) so I mostly just left
those alone too, with a few spots modified to re-use fmtlib's lossy
utf8.

Some of the changes are basically never gonna be hit IRL, like who would
put a file with a non-ascii _extension_ along with their modules? But
the diff is (I hope) pretty easy to validate as OK.

Testing has been somewhat minimal, I fired up the GCC build of spice2x
in a dodgy folder name, got mojibake (running via wine in linux so take
that as you will), ran the unmodified clang spice and crashed the same
way the reporter did. After modification, I get the exact same mojibake
so I assume if the terminal enjoys utf8 it'll display OK.

Claude (only used for review) thinks the commit is fine but is annoyed
that I use `fmt::detail` in the appdata censoring, which is part of the
private API; personally I don't care because it's pretty stable.

src/spice2x/misc/eamuse.cpp

@@ -87,7 +87,7 @@ bool eamuse_get_card(const std::filesystem::path &path, uint8_t *card, int index
     std::unique_lock<std::mutex> lock(CARD_OVERRIDES_LOCK);
     const auto card_override = CARD_OVERRIDES[index];
     lock.unlock();
-    
+
     // Check if card overrides are present
     if (!card_override.empty()) {
 
@@ -131,7 +131,7 @@ bool eamuse_get_card_from_file(const std::filesystem::path &path, uint8_t *card,
     // open file
     std::ifstream f(path);
     if (!f) {
-        log_warning("eamuse", "{} can not be opened!", path.string());
+        log_warning("eamuse", "{} can not be opened!", path);
         return false;
     }
 
@@ -142,7 +142,7 @@ bool eamuse_get_card_from_file(const std::filesystem::path &path, uint8_t *card,
 
     // check size
     if (length < 16) {
-        log_warning("eamuse", "{} is too small (must be at least 16 characters)", path.string());
+        log_warning("eamuse", "{} is too small (must be at least 16 characters)", path);
         return false;
     }
 
@@ -160,14 +160,14 @@ bool eamuse_get_card_from_file(const std::filesystem::path &path, uint8_t *card,
         if (!digit && !character_big && !character_small) {
             log_warning("eamuse",
                 "{} contains an invalid character sequence at byte {} (16 characters, 0-9/A-F only)",
-                path.string(), n);
+                path, n);
 
             return false;
         }
     }
 
     // info
-    log_info("eamuse", "[P{}] Inserted {}: {}", index+1, path.string(), buffer);
+    log_info("eamuse", "[P{}] Inserted {}: {}", index+1, path, buffer);
 
     // convert hex to bytes
     hex2bin(buffer, card);
@@ -454,7 +454,7 @@ uint16_t eamuse_get_keypad_state(size_t unit) {
     if (unit >= std::size(KEYPAD_STATE)) {
         return 0;
     }
-    
+
     // reset
     KEYPAD_STATE[unit] = KEYPAD_STATE_OVERRIDES[unit];
     KEYPAD_STATE[unit] |= KEYPAD_STATE_OVERRIDES_BT5[unit];