[FEATURE] Let users Search all existing text messages

[dunkeltron]

Currently if a user wants to find a specific phrase in a conversation they have to manually scroll and load messages.

It would be a benefit if the user could open a "search conversation" input field to enter the desired search string.

we would have to write:

• [ ] a php endpoint that grabs all messages that contain the matching search string in a conversation
• [ ] A Vue Component that handles the user search string input
• [ ] A method for meaningfully displaying the results