Support the ability to disable worker process count configuration

We need the ability to disable worker process count configuration and worker process count changes (use of `FUNCTIONS_WORKER_PROCESS_COUNT` and `FUNCTIONS_WORKER_DYNAMIC_CONCURRENCY_ENABLED`) in environments that do not support running multiple language workers.

Search the Azure Functions host for FUNCTIONS_WORKER_PROCESS_COUNT and FUNCTIONS_WORKER_DYNAMIC_CONCURRENCY_ENABLED, then trace where their configuration and changes are handled. The work is done when environments that cannot run multiple language workers can disable both worker process count configuration and worker process count changes, with the relevant behavior covered by tests.

Written by the indexing model from the issue text.