add tutorials for cross encoder models on Amazon Bedrock (opensearch-…

…project#3278)

* add tutorials for cross encoder models on Amazon Bedrock

Signed-off-by: tkykenmt <tkykenmto+github.com@gmail.com>

* fix bedrock url to reflect region parameter

Signed-off-by: tkykenmt <tkykenmto+github.com@gmail.com>

* update error handling to throw exception when post processing function recieve empty result from a model.

Signed-off-by: tkykenmt <tkykenmto+github.com@gmail.com>

* fix tutorials for cross encoder models on Amazon Bedrock based on review comments on opensearch-project#3278

Signed-off-by: tkykenmt <tkykenmto+github.com@gmail.com>

* fix wrong service name on tutorials for cross encoder models on Amazon Bedrock opensearch-project#3278

Signed-off-by: tkykenmt <tkykenmto+github.com@gmail.com>

* fix some notes on tutorials for cross encoder models on Amazon Bedrock opensearch-project#3278

Signed-off-by: tkykenmt <tkykenmto+github.com@gmail.com>

* some minor fix

Signed-off-by: Yaliang Wu <ylwu@amazon.com>

* change cross-encoder to rerank

Signed-off-by: Yaliang Wu <ylwu@amazon.com>

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Signed-off-by: tkykenmt <tkykenmto+github.com@gmail.com>
Signed-off-by: Yaliang Wu <ylwu@amazon.com>
Co-authored-by: Yaliang Wu <ylwu@amazon.com>