Support CREATE EXTERNAL TABLE using DataFusion

[gohalo]

Just like the java client routies.

HoodieTableMetaClient.withPropertyBuilder()
        .setTableType(HoodieTableType.MERGE_ON_READ)
        .setTableName(tableName)
        .setTableCreateSchema(SCHEMA)
        .setPayloadClassName(HoodieAvroPayload.class.getName())
        .initTable(conf, tablePath);

Currently, got some problems.

1. object_store crate doesn't support to create directory. Because of the struct Path which without leading or trailing delimiters.

pub struct Path {
    /// The raw path with no leading or trailing delimiters
    raw: String,
}

But in most of cloud object store including minio, you could put empty to some path like /data/example/.hoodies/. Maybe we could change the value of private raw in the struct Path with unsafe codes, or, create some marker files like .hoodies/.schema/marker.

2. We should create compatiable config files for Java properties, especilly for hoodies.properties.

[xushiyan]

we are not prioritizing write support at this moment. let's pivot this issue to support create external table in datafusion https://datafusion.apache.org/user-guide/sql/ddl.html#create-external-table

@jonathanc-n are you interested in picking this up? would you share some high-level implementation points?

[jonathanc-n]

High level implementation:

• Have tableproviderfactory validate parameters for creating an instance of CreateExternalTable.
• Since we are currently focusing on read capabilities, add read table
  What exactly were you looking for create external table to be able to do, since there is already some functionality for it.

[jonathanc-n]

For example, https://github.com/apache/hudi-rs/blob/main/crates/datafusion/src/lib.rs#L291 has a solid test or the functionality. What functionality would you like to target on top of this?

[xushiyan]

@jonathanc-n you're right, i almost forgot this is actually a dup of #150 we should update the readme to reflect the usage, and add a module example to show this in datafusion/lib.rs

[xushiyan]

Closing this due to being a dup. @jonathanc-n pls feel free to file a PR to update the docs if you're keen. I'll keep a todo for myself also for an overall docs update before working on the release.

@jonathanc-n you're right, i almost forgot this is actually a dup of #150 we should update the readme to reflect the usage, and add a module example to show this in datafusion/lib.rs