Fix AbortController support in test application https://github.com/realm/realm-js/pull/3159/files#diff-d26a706ae4575d015e87f94162bbd89bR21
https://github.com/realm/realm-js/pull/3159/files#diff-6523ddb3afeab06bc23fb6db4bc56f4fR36
https://github.com/realm/realm-js/pull/3159/files#diff-d7244d751b85d9365de7f5e842a1a745R34

Fix testNoMigrationOnSync tests https://github.com/realm/realm-js/pull/3159/files#diff-5d2b8a87815f0d97af23d120cfaf5ca5R1618

Fix jest CI tests when jest issue investigation is done https://github.com/realm/realm-js/pull/3159/files#diff-c12ed423720858d3e4d1e9625f0aafb2R3

Fix all Todo items where //TODO: remove when MongoDB Realm test server can be hosted on Mac or other options exists is present