Combine `ParsedRuntimeEnv` and `RuntimeEnv` into `ray.runtime.RuntimeEnv`, details: #21495
- The `new RuntimeEnv` includes all external interfaces of `ParsedRuntimeEnv` and `old RuntimeEnv`.
- The `new RuntimeEnv` will be exposed directly to the user.
- example:
```python
runtime_env = ray.runtime_env.RuntimeEnv(working_dir="s3://workding_dir.zip",
pip=["requests"],
java_jars=["s3://jar1.zip"],
java_jvm_options=["-Dxxx=xxx"])
```
