feat: (generic realm) expansion

[joe0BAB]

We want a generic logic that allows to "resolve a realm".

Example: Let docker/auth/** be a realm. Then, the pattern query **/foo should get resolved to docker/auth/**/foo.

We can define ** to be a generic realm. Then this reframes our problem into a "generic realm replacement problem".

As there could be n generic realms, more generally speaking we can view this a "replace n" problem where we have a component string and up to n realm markers ** that should be replaced.

[Benehiko]

now that we only have 1 replace wouldn't this end up like:

pattern: docker/**/bar/**
input ID: bob
output: docker/bob/bar/**

[joe0BAB]

So we could implement what you're describing, but right now it isn't. Instead if the candidate positions where we could replace are not equal 1, we return an error.

I'm hesitant to do this as eg the following could be a bit surprising:

pattern: docker/**/bar/**
input Pattern: bob/**
output: docker/bob/**/bar/**

🤷

[joe0BAB]

It also complicates things as with

pattern: docker/**/bar/**
input ID: bob
output: docker/bob/bar/**

you're converting an ID into a pattern. Then it wouldn't be ExpandID(ID) (ID, error) anymore.

[Benehiko]

yes, i was asking if the output would be not should be.