Routing: Serialize matcher for iOS

[hossinasaadi]

I've implemented serialization for MphMatcherGroup and the memory usage decreased.
Same rules, This PR : 22 MB, Serialized : 14-15 MB

So far, I've done the following:
• Added a function to prebuild matchers from the config, keyed by ruleTag
• Serialized all rule matchers and saved them to a file
• Loaded the serialized data via mmap and applied it directly to routing conditions
• Add xray.cached.matcher flag for apply matcher form file
• Add function for build the matcher.cache from config json string (BuildDomainMatcherCache to RouterConfig)

#5488 (comment)
@RPRX @iambabyninja @mangustyura

Details :

1- required rules to have ruleTag :

{
   "domain" : [
     "domain:alidns.com",
     "domain:doh.pub",
     "domain:dot.pub",
     "domain:360.cn",
     "domain:onedns.net",

     "geosite:cn"

   ],
   "outboundTag" : "direct",
   "ruleTag" : "rule-1"
 },
 {
   "ip" : [
     "223.5.5.5",
     "223.6.6.6",
     "2400:3200::1",
     "2400:3200:baba::1",

     "geoip:cn"
   ],
   "outboundTag" : "direct",
   "ruleTag" : "rule-2"
 }

2- Cached file should be alongside the geofiles and file name should be matcher.cache

3- Sample code for pre-built domain matcher :

func makeDomainMatcherCache(configPath string, assetsDir string) error {
	os.Setenv("XRAY_LOCATION_ASSET", assetsDir)

	xrayBytes, err := os.ReadFile(configPath)
	if err != nil {
		return err
	}
	var xray conf.Config
	err := json.Unmarshal(xrayBytes, &xray)
	if err != nil {
		return nil
	}

	err = xray.RouterConfig.BuildDomainMatcherCache()
	if err != nil {
		return err
	}

	return nil
}

[hossinasaadi]

ready to test.

[RPRX]

2- Cached file should be alongside the geofiles and file name should be matcher.cache

配置文件内 Routing 加个配置项来指定名称吧，同时也是开启该功能的标志，不然开多个 Xray 会炸，DNS 的你也看一下

[RPRX]

@yiguodev libXray 或许需要更新 BuildDomainMatcherCache()

[RPRX]

本来以为 mmap 是把磁盘空间当运行内存用结果它确实是懒加载，不知道会不会像 swap，不过仍然 https://t.me/projectXtls/1384

当然 Xray 启动时也不再需要 read、unmarshal geosite、build 出完整的 DomainMatcher 从而降低了 peak memory usage

有了这项优化，前面的 123 全被解决了，重新拾起 pre-map 也没必要了

[iambabyninja]

@RPRX, could you please advise which of the three PRs (
#5499
#5488
#5505
) should be tested on iOS?

We are ready to make a test build now.

[RPRX]

@iambabyninja 要测试的是这个 PR，不过由于该伊朗贡献者目前失联了所以新版本暂时不会包括这个 PR