Add fix for event security (MessageEvent source issue)

[david0xd]

This PR will fix an issue after changing the prototype of the MessageEvent (source property).

This PR will unblock: MetaMask/snaps#1221

Related ticket: MetaMask/snaps#1132

Context

• As part of the effort around securing snaps arch, we decided to scuttle all properties of Event based prototypes that might leak DOM/window objects.
• However, when performing such scuttling, this dep is being affected because it counts on having a direct access to those properties that we scuttle.
• We fix that by simply preserving the needed descriptors before we scuttle them so we can use them later instead of the direct props access.

[weizman]

Explanation (context)

• As part of the effort around securing snaps arch, we decided to scuttle all properties of Event based prototypes that might leak DOM/window objects.
• However, when performing such scuttling, this dep is being affected because it counts on having a direct access to those properties that we scuttle.
• We fix that by simply preserving the needed descriptors before we scuttle them so we can use them later instead of the direct props access.

[weizman]

Are all those ts-expect-error really needed? no way around those?