SystemMonitor: Default initialize all thread state variables

Having bogus values here when we just initialize the thread state with a
process can lead to all sorts of bad things down the line, like infinite
draws.

Userland/Applications/SystemMonitor/ProcessModel.h

@@ -94,41 +94,41 @@ private:
     struct Process;
 
     struct ThreadState {
-        pid_t tid;
+        pid_t tid { 0 };
-        pid_t pid;
+        pid_t pid { 0 };
-        pid_t ppid;
+        pid_t ppid { 0 };
-        pid_t pgid;
+        pid_t pgid { 0 };
-        pid_t sid;
+        pid_t sid { 0 };
-        u64 time_user;
+        u64 time_user { 0 };
-        u64 time_kernel;
+        u64 time_kernel { 0 };
-        bool kernel;
+        bool kernel { false };
-        String executable;
+        String executable { "" };
-        String name;
+        String name { "" };
-        uid_t uid;
+        uid_t uid { 0 };
-        String state;
+        String state { "" };
-        String user;
+        String user { "" };
-        String pledge;
+        String pledge { "" };
-        String veil;
+        String veil { "" };
-        u32 cpu;
+        u32 cpu { 0 };
-        u32 priority;
+        u32 priority { 0 };
-        size_t amount_virtual;
+        size_t amount_virtual { 0 };
-        size_t amount_resident;
+        size_t amount_resident { 0 };
-        size_t amount_dirty_private;
+        size_t amount_dirty_private { 0 };
-        size_t amount_clean_inode;
+        size_t amount_clean_inode { 0 };
-        size_t amount_purgeable_volatile;
+        size_t amount_purgeable_volatile { 0 };
-        size_t amount_purgeable_nonvolatile;
+        size_t amount_purgeable_nonvolatile { 0 };
-        unsigned syscall_count;
+        unsigned syscall_count { 0 };
-        unsigned inode_faults;
+        unsigned inode_faults { 0 };
-        unsigned zero_faults;
+        unsigned zero_faults { 0 };
-        unsigned cow_faults;
+        unsigned cow_faults { 0 };
-        unsigned unix_socket_read_bytes;
+        unsigned unix_socket_read_bytes { 0 };
-        unsigned unix_socket_write_bytes;
+        unsigned unix_socket_write_bytes { 0 };
-        unsigned ipv4_socket_read_bytes;
+        unsigned ipv4_socket_read_bytes { 0 };
-        unsigned ipv4_socket_write_bytes;
+        unsigned ipv4_socket_write_bytes { 0 };
-        unsigned file_read_bytes;
+        unsigned file_read_bytes { 0 };
-        unsigned file_write_bytes;
+        unsigned file_write_bytes { 0 };
-        float cpu_percent;
+        float cpu_percent { 0 };
-        float cpu_percent_kernel;
+        float cpu_percent_kernel { 0 };
         Process& process;
 
         ThreadState(Process& argument_process)