fix: 3657 #3657

[mengnankkkk]

What this PR does / why we need it?

Found that the maxLevel limit in the JSONWriter class is hard-coded to 2048
Context uses defaultMaxLevel when initialized but there is no public API to modify it

Summary of your change

Added two new public methods in JSONFactory.java

Please indicate you've done the following:

• Made sure tests are passing and test coverage is added if needed.
• Made sure commit message follow the rule of Conventional Commits specification.
• Considered the docs impact and opened a new docs issue or PR with docs changes if needed.

[wenshao]

你需要在本地运行mvn validate来修复checkstyle的问题

[daovjnhs2]

版本：fastjson2.0.62
我想要去配置maxlevel，我在fastjson2.properties中配置了maxlevel，但是这里的读取逻辑有问题，无法读取到我properties中的配置