Add IE testing and guard proxies when they are not present

[igorT]

We were not testing against IE11, and a few failures had snuck in. We now only create m3 array proxies when we are able to instantiate a Proxy class, similarly to how Ember does it https://github.com/emberjs/ember.js/blob/v3.28.0/packages/@ember/-internals/utils/lib/proxy-utils.ts

[github-actions]

Performance Report for 28856cc

Scenario - materializing: ✅ Performance improved

✅ duration
phase estimated improvement -61ms [-104ms to -17ms] OR -1.09% [-1.86% to -0.31%]
☑️ Phase [navigationStart] => [start-loading]
phase no difference [-3ms to 9ms]
✅ Phase [start-loading] => [pushed-payload]
phase estimated improvement -40ms [-67ms to -15ms] OR -1.29% [-2.16% to -0.47%]
✅ Phase [pushed-payload] => [end-loading]
phase estimated improvement -21ms [-41ms to -2ms] OR -0.97% [-1.9% to -0.12%]
☑️ Phase [end-loading] => [Test End]
phase no difference [-1ms to 1ms]

Scenario - rendering: ☑️ Performance is stable

☑️ duration
phase no difference [-13ms to 16ms]
☑️ Phase [navigationStart] => [start-loading]
phase no difference [-3ms to 6ms]
☑️ Phase [start-loading] => [pushed-payload]
phase no difference [-1ms to 2ms]
☑️ Phase [pushed-payload] => [end-loading]
phase no difference [0ms to 1ms]
☑️ Phase [end-loading] => [Test End]
phase no difference [-14ms to 7ms]

[igorT]

@hjdivad gave 👍 over slack