feat: add java sdk for lancedb cloud rest endpoints

[LuQQiu]

Closes #112

Example usage can be found in RestTableApiTest.
Added the java sdk for lancedb cloud endpoints

[LuQQiu]

Java SDK limitations:
OpenApI are not good at recursive structs. We have two known places that has recursive structs.

1. Schema:

• affect describe calls, JsonSchema -> JsonField -> JsonDataType -> JsonField

/// JSON representation of an Apache Arrow [Field].
#[derive(Serialize, Deserialize, Debug, ToSchema)]
pub struct JsonField {
    name: String,
    #[serde(rename = "type")]
    type_: JsonDataType,
    nullable: bool,

    #[serde(skip_serializing_if = "Option::is_none")]
    metadata: Option<HashMap<String, String>>,
}
/// JSON representation of an Apache Arrow [DataType].
#[derive(Serialize, Deserialize, Debug, ToSchema)]
pub struct JsonDataType {
    #[serde(rename = "type")]
    type_: String,
    #[serde(skip_serializing_if = "Option::is_none")]
    #[schema(value_type = Object)]
    fields: Option<Vec<JsonField>>,
    #[serde(skip_serializing_if = "Option::is_none")]
    length: Option<usize>,
}

2. FTS:

• affect advanced FTS query.

#[derive(Debug, Clone, PartialEq, Serialize, Deserialize, ToSchema)]
#[serde(rename_all = "snake_case")]
pub enum FtsQuery {
    // leaf queries
    Match(MatchQuery),
    Phrase(PhraseQuery),

    // compound queries
    Boost(BoostQuery),
    MultiMatch(MultiMatchQuery),
    // Openapi generator does not support recursive schema
    #[schema(value_type = Object)]
    Boolean(BooleanQuery),
}

#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct BooleanQuery {
    pub should: Vec<FtsQuery>,
    pub must: Vec<FtsQuery>,
    pub must_not: Vec<FtsQuery>,
}

[jackye1995]

For the java test failure https://github.com/lancedb/lance-namespace/actions/runs/16271890098/job/45942087077?pr=130, let's just remove JDK8 from the test matrix

[jackye1995]

I think for APIs that are conflicting with the current Lance Namespace APIs, we should mark the LanceDB ones as V1, and bump the Lance Namespace API operation version as V2. This also paves a way for existing customers to migrate.

[LuQQiu]

@jackye1995 Done, added back conflicting describe table call as V2, please take a look

[jackye1995]

looks good to me!