add missing mergequeue rule configuration properties

[patrickcarnahan]

the merge queue configuration is missing a couple of properties that are available in the raw api:

{
    "type": "merge_queue",
    "parameters": map[string]interface{}{
        "merge_method":                      "MERGE",
        "max_entries_to_build":              5,
        "min_entries_to_merge":              1,
        "max_entries_to_merge":              5,
        "min_entries_to_merge_wait_minutes": 1,
        "grouping_strategy":                 "ALLGREEN",
        "check_response_timeout_minutes":    60,
        "check_run_retries_limit":           0,
        "actor_controlled_merging":          true,
    },
}

the current support in the merge queue ruleset is represented by the existing struct:

// MergeQueueRuleParameters represents the merge_queue rule parameters.
type MergeQueueRuleParameters struct {
	MergeMethod                  MergeQueueMergeMethod `json:"merge_method"`
	MaxEntriesToBuild            int                   `json:"max_entries_to_build"`
	MinEntriesToMerge            int                   `json:"min_entries_to_merge"`
	MaxEntriesToMerge            int                   `json:"max_entries_to_merge"`
	MinEntriesToMergeWaitMinutes int                   `json:"min_entries_to_merge_wait_minutes"`
	GroupingStrategy             MergeGroupingStrategy `json:"grouping_strategy"`
	CheckResponseTimeoutMinutes  int                   `json:"check_response_timeout_minutes"`
}

from this diff we need to implement two additional properties:

CheckRunRetriesLimit   int  `json:"check_run_retries_limit"`
ActorControlledMerging bool `json:"actor_controlled_merging"`

i'm happy to self-assign and add this functionality myself if there is reasonable expectation it will be merged.

[patrickcarnahan]

went ahead and opened a pull request to add these properties since it was pretty straight-forward. i don't believe there is anything else to be done on the PR but happy to course correct as necessary.

[patrickcarnahan]

mentioned this in the pr but these properties aren't documented nor are they available for most organizations or repos, so will take a different approach as these will not apply for the majority of use cases.