Create Python REST Library for Elasticsearch/OpenSearch

[chelma]

Task

Per investigation/discussion as a part of #48 and #7, it was decided that rather than use a specific language client's abstraction for interacting with the UTF's clusters and determining the outcome of tests based on the deserialized language objects, we should instead interact w/ the clusters at the REST layer and base our test outcomes on that layer instead. This helps reduce the odds the UTF does produces different results than seen by customers of the base REST interface that is the key abstraction between client/server. As a result, we need to create a library that wraps and presents the REST interface of ES/OS clusters to the UTF.

Acceptance Criteria

• Create a Python REST-centric library for interacting with the ES 7.10.2/OS 1.3.6 clusters used to demonstrate snapshot/restore in this Issue (Create Framework Step that executes Snapshot/Restore upgrade #7) and this PR(UTF able to snapshot from ES 7.10.2 and restore onto OS 1.3.6 #47)
• Replace all CURL calls in the UTF with the REST-centric library

[chelma]

Have the code written up for this an the FrameworkSteps updated to use it. Just need to add unit tests. Should have a PR out tomorrow.

[chelma]

PR for this task posted - #55

[chelma]

Code merged; resolving.