Refactor runtime type checker concurrency model #8876

Job	Run time
Build Ballerina Lang	7m 38s
Build Ballerina Distribution	1h 39m 8s
Build Stdlib Level (1)	4m 53s
Build Stdlib Level (10)	11m 31s
Build Stdlib Level (2)	13m 17s
Build Stdlib Level (3)	4m 58s
Build Stdlib Level (4)	16m 17s
Build Stdlib Level (6)	1h 39m 10s
Build Stdlib Level (5)	1h 39m 9s
Build Stdlib Level (7)	1h 39m 8s
Build Stdlib Level (8)	1h 35m 51s
Build Stdlib Level (9)	4m 31s
	9h 15m 31s

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