Support Category in Tags #305
Description
We are using tags to store information about the tests. But tags are just strings, so we don't know if the tag is a test type, a component or an owner.
Let's have a convention be that if you start your tag with a string ending in a colon, followed by another string, then the string before the colon is a category and the string after is the value. So for example, I might send three tags: "Component:metrics-server", "TestType:acceptance", "Owner:capitola". This would indicate the test is an acceptance test for the metrics-server component and it is owned by the Capitola team.
We will want to be able to pull out the tags by category, so let's store that in a new column in the tag table, along with the value. We can keep the original, unparsed value in the tag table.