#2305 Implement in-app notifications for non-monetary contributions

[SebinSong]

closes #2305

Currently there is two places where users can add/remove/update their non-monetary contributions: 1. /contributions page. 2. IncomeDetails.vue modal.

In 1., the item is added/removed/updated one by one. Whereas in 2., multiple items can be added/removed/updated at a time. In this case, the notification sentence can have compound expressions (not sure if this is a correct english words but anyways) eg. Teach Javascript and 2 more or added Teach Python and removed Teach how to play piano and 1 more etc.

Clicking on the notification messages navigates to /contributions page where they can see the full list of the group's non-monetary contributions.

Hope it looks good.

[cypress[bot]]

group-income    Run #3131

Run Properties:   Passed #3131  •  ee832ee8d4 ℹ️: Merge 7149a75bfa65c90088bd79b0cf4adc13cdf28bc6 into 8138b12f6d70ad9447e338047d41...

Project	group-income
Branch Review	sebin/task/#2305-notifications-for-non-monetary
Run status	Passed #3131
Run duration	09m 13s
Commit	ee832ee8d4 ℹ️: Merge 7149a75bfa65c90088bd79b0cf4adc13cdf28bc6 into 8138b12f6d70ad9447e338047d41...
Committer	Sebin Song
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Flaky	0
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[SebinSong]

This PR is ready besides the group-chat heisen-bug

[taoeffect]

Thanks @SebinSong. Supposedly @corrideat thinks his PR #2294 (once it's ready) should address the heisenbug.