Add config to control whether json values are escaped

[esterTion]

This PR adds a new config key EscapeJsonValues, which controls whether unicode and special characters are escaped.
See UnsafeRelaxedJsonEscaping

The default value for missing the key is false, which makes the new version of Il2cppDumper behaves the same as old version prior to this change

[esterTion]

从Newtonsoft.Json换成System.Text.Json之后默认会转义所有的unicode，今天进去搜字符串还愣了一下
新加的配置默认缺键时为false不转义，这样从旧版本直接换程序升级的可以保持和旧版本行为保持一致