Adding asynchronous features to harness

[hardingalexh]

Most of the setter functions are not asynchronous. This is not desirable because we often have use cases for using asynchronous code (ie: fetch requests) within beforeSet/afterSet functions as well as loadData itself.

• Make setFilter async
• Make loadData async
• Make setChartData async
• Ensure that all of the above wait on their respective before/after set functions

[andykawabata]

After realizing that making certain function async would not allow us to await a subscription relative to the trigger we decided to go with a different approach. Alex specified:

what if HVB just ran setFilter, and harness itself had the check for synchronous and running of loadData? if so, we formalize the synchronous behavior instead of having that be a side effect of the component package. and if we do, we can put that check into the subscription block so that it explicitly runs after user-defined afterSet behaviors

we’d be altering the subscribeActions function in here: https://github.com/RTIInternational/harness-vue/blob/main/src/store/subscriptions.js
so that in before we would await runSubscriptions, and in after we would await runSubscriptions, then add a check that looks for setFilter with synchronous set to false and then await loadData