## Description

To simplify the changes required for this PR, we removed the
experimental flag for dynamic configuration. This helps to remove the
extra code needed to support only static configuration.

The main changes in this PR are:
1. The current dynamic partition config is tracked in
`PartitionContext`. The initial value of it is received when the
partition is bootstrapped. We reuse the `DynamicPartitionConfig` defined
in `ClusterConfiguration`. Alternately, we can define a new object
internal to `partitions`. But at the moment, it will look identical to
the other one. So to keep it simple, we reused the existing class. When
we add new configuration parameters to it, we can define a new one if
needed.
2. When a config is changed, a call back to the `PartitionManager` will
be invoked. The implementation of this call back reacts to the
configuration change and also updates the config in the
`PartitionContext`. In this case, the call back is
`PartitionManager::disableExporter` which disables the exporter in
`ExporterDirector`.
3. `ExporterDirectorTransitionStep` reads the latest config and uses
that to initialize the exporters during role transitions. Only enabled
exporters are given to the `ExporterDirector`. Thus already disabled
exporters are not re-enabled.

## Related issues

closes #18419

## Description

To simplify the changes required for this PR, we removed the
experimental flag for dynamic configuration. This helps to remove the
extra code needed to support only static configuration.

The main changes in this PR are:
1. The current dynamic partition config is tracked in
`PartitionContext`. The initial value of it is received when the
partition is bootstrapped. We reuse the `DynamicPartitionConfig` defined
in `ClusterConfiguration`. Alternately, we can define a new object
internal to `partitions`. But at the moment, it will look identical to
the other one. So to keep it simple, we reused the existing class. When
we add new configuration parameters to it, we can define a new one if
needed.
2. When a config is changed, a call back to the `PartitionManager` will
be invoked. The implementation of this call back reacts to the
configuration change and also updates the config in the
`PartitionContext`. In this case, the call back is
`PartitionManager::disableExporter` which disables the exporter in
`ExporterDirector`.
3. `ExporterDirectorTransitionStep` reads the latest config and uses
that to initialize the exporters during role transitions. Only enabled
exporters are given to the `ExporterDirector`. Thus already disabled
exporters are not re-enabled.

## Related issues

closes #18419