Ability to search for numbers by substring

[regaldude]

Checklist

• [x] I am using the latest version - 1.4.3
• [x] I checked, but didn't find any duplicates (open OR closed) of this issue in the repo.
• [x] This issue contains only one feature request. I will open one issue for every feature I want to request.

Describe the feature you want

Allow for searching numbers by a substring.

Is your feature request related to a problem? Please describe it

Currently, phone number search has to match exactly from the beginning of the saved number. This makes it difficult to search for numbers with country codes in them.

For example, if I have a contact saved with number "+44 123 456 7890", this number won't show up if start my search with "123.."

How will you/everyone benefit from this feature?

Would make search much more convenient to use since there might be several saved numbers with country codes.

This is also the behaviour in AOSP phone app.