feat: Enforce request maximum size and number of logs

[mrsillydog]

Proposed Change

Google SecOps (Chronicle) limits API log ingestion in two different ways - first, in uncompressed request size, and secondly in number of logs per request. This PR changes the implementation of the chronicle exporter to respect these limits by checking against them before sending, and then splitting up the batched request logging data if either limit is exceeded. These limits are configurable on the SecOps backend, and therefore now are also configurable in the exporter.

Possible concerns:

• Is proto.Size() an accurate measurement for the HTTP protocol workflow? It was confirmed as accurate for the GRPC protocol workflow.
• What is a reasonable default size limit for HTTP and GRPC? The documentation lists it as 1MB for the GRPC endpoint, undocumented for the HTTP endpoint. Manual testing confirmed our configured limit is 5 MiB via GRPC, but substantially higher (unclear exactly what the limit is) via the v1alpha HTTP endpoint.

Checklist

• Changes are tested
• CI has passed