[FSSDK-10201] queueMicrotask alternative for unsupported platforms

[junaed-optimizely]

Summary

JS SDK should fall back to setTimeout when queueMicrotask is unavailable in an embedded environment

Test plan

Unit test has been added for the change

Issues

FSSDK-10201

[coveralls]

coverage: 90.3% (-0.008%) from 90.308%
when pulling e3dae0c on junaed/FSSDK-10201
into 851b066 on master.

[muzahidul-opti]

LGTM. The changes are well-structured and improve the codebase. However, it would be beneficial to add test cases to ensure the new functionality works as expected.

[coveralls]

coverage: 90.311% (+0.003%) from 90.308%
when pulling 4d09d4c on junaed/FSSDK-10201
into 851b066 on master.

[coveralls]

coverage: 23.012% (-67.3%) from 90.308%
when pulling 39c8f72 on junaed/FSSDK-10201
into 851b066 on master.

[coveralls]

coverage: 90.308%. remained the same
when pulling 17ea6f4 on junaed/FSSDK-10201
into 851b066 on master.

[coveralls]

coverage: 90.307% (-0.001%) from 90.308%
when pulling 8002ade on junaed/FSSDK-10201
into 851b066 on master.