Improve repository finder search URL validation

[filiptronicek]

Description

Adds generic validation for git URLs when inputting into the "New Workspace" repository search bar.

Supported are both full URLs (https://, http://, ssh://, git://) as well as SSH clone URLs (like [email protected]:gitpod-io/gitpod.git).

Related Issue(s)

Fixes ENT-596

How to test

1. See tests I added for this
2. Go to https://ft-better-374e81d1de.preview.gitpod-dev.com/new and play around with the input

[mustard-mh]

Unit tests passed, and tried basic path on dashboard, it works well with prefix like https://

nit: Use /# url directly will not check? i.e. https://ft-better-374e81d1de.preview.gitpod-dev.com/#github.com/gitpod-io/gitpod (I used to use this format, sad to see it's not supported anymore)

[filiptronicek]

@mustard-mh that's a regression, I think we should still support implicit HTTP URLs without a protocol. Will raise a PR for that

Seems this is functioning as it always has. Check gitpod.io for the old version. Here is my try on the old input and as you can see there's no suggestion to use the URL.