Support parsing escaped characters for PX_Lexer

[woodzn]

Solve the problem that escaped characters cannot be parsed in JSON

test code

#include"PX_Core.h"#include"PX_Kernel.h"charbuff[1024*1024];
intmain() {
PX_Jsonjson;
px_memorypoolmp;
char*p="{\"hello\":\"\\\"\"}";
mp=MP_Create(buff, 1024*1024);
PX_JsonInitialize(&mp,&json);
px_boolok=PX_JsonParse(&json,p);
if (!ok) {
printf("JSON parse error\n");
}
else {
constchar*v=PX_JsonGetString(&json,"hello");
printf("%s:%s\n","hello",v);
}
}

Program output before repair

JSON parse error

Now the program outputs

hello:"