Better error message when trying to open a Collection with Client.open

[gadomski]

Related Issue(s):

• Closes Client.open and collections #103

Description: After digging a bit, I think it does not make sense to allow Client.open to work for collections, since we have ClientCollection to handle that case. This PR improves the error message when trying to open a collection with Client.open.

Now:

$ stac-client search https://planetarycomputer.microsoft.com/api/stac/v1/collections/sentinel-2-l2a
Could not open Client (href=https://planetarycomputer.microsoft.com/api/stac/v1/collections/sentinel-2-l2a), expected type=Catalog, found type=Collection

Before:

$ stac-client search https://planetarycomputer.microsoft.com/api/stac/v1/collections/sentinel-2-l2a
{'id': 'sentinel-2-l2a', 'type': 'Collection', <snip>...</snip> L2A (bottom-of-atmosphere).'} does not represent a Client instance

PR Checklist:

• Code is formatted
• Tests pass
• Changes are added to the CHANGELOG

[codecov-commenter]

Codecov Report

Merging #222 (7f4b7fb) into main (e0166d3) will increase coverage by 0.21%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #222      +/-   ##
==========================================
+ Coverage   83.75%   83.96%   +0.21%     
==========================================
  Files           9       10       +1     
  Lines         677      686       +9     
==========================================
+ Hits          567      576       +9     
  Misses        110      110              

Impacted Files	Coverage Δ
pystac_client/client.py	81.94% <100.00%> (+1.94%)	⬆️
pystac_client/errors.py	100.00% <100.00%> (ø)

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[philvarner]

One other related issue is that we have a bunch of methods that have tying that they return ClientCollection, but if a StacIO instance that's not a StacApiIO is used, they actually just return a Collection. I'm not sure what expectations from a user would be in these cases.

[gadomski]

One other related issue is that we have a bunch of methods that have tying that they return ClientCollection, but if a StacIO instance that's not a StacApiIO is used, they actually just return a Collection. I'm not sure what expectations from a user would be in these cases.

My initial instinct is that it should error -- changing the type of a method's return value based on the type of a member feels very funny. But I don't have a full sense of the implications of that change, or the cases where someone would be returning a ClientCollection.