Refactor runtime type checker concurrency model #8887

Job	Run time
Build Ballerina Lang	8m 15s
Build Ballerina Distribution	1h 12m 25s
Build Stdlib Level (1)	4m 7s
Build Stdlib Level (10)	12m 41s
Build Stdlib Level (2)	13m 15s
Build Stdlib Level (3)	9m 54s
Build Stdlib Level (4)	14m 38s
Build Stdlib Level (5)	2h 0m 14s
Build Stdlib Level (6)	5m 54s
Build Stdlib Level (7)	3m 49s
Build Stdlib Level (9)	5m 16s
Build Stdlib Level (8)	1h 32m 25s
	6h 2m 53s

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