Add "withChannel" parameter for search and get

[fredex42]

What does this change?

Exposes the functionality introduced in https://github.com/guardian/content-api/pull/2882, by allowing a user to search within a channel using a "withChannel()" builder method on the query:

ContentApiClient.search().withChannel("my-channel").....
ContentApiClient.item("item-path").withChannel("my-channel")...

Adds a ".showChannels()" builder to expose the "show-channels=' query param

Mark recipe atom search as deprecated prior to removal

How to test

Tests are provided in the spec files, duplicate this in your own project

How can we measure success?

Able to make channelled requests with CSC

[github-actions]

Test Results

0 tests  ±0   0 ✅ ±0   0s ⏱️ ±0s
0 suites ±0   0 💤 ±0 
0 files   ±0   0 ❌ ±0 

Results for commit 5c27188. ± Comparison against base commit e75598d.

♻️ This comment has been updated with latest results.

[gu-scala-library-release]

@fredex42 has published a preview version of this PR with release workflow run #56, based on commit 40cbea1:

30.0.0-PREVIEW.agchannel-namespace-search.2024-06-12T1536.40cbea1d

Want to make another preview release?

Click 'Run workflow' in the GitHub UI, specifying the ag/channel-namespace-search branch, or use the GitHub CLI command:

gh workflow run release.yml --ref ag/channel-namespace-search

Want to make a full release after this PR is merged?

Click 'Run workflow' in the GitHub UI, leaving the branch as the default, or use the GitHub CLI command:

gh workflow run release.yml

[gu-scala-library-release]

@fredex42 has published a preview version of this PR with release workflow run #57, based on commit 45bea49:

30.0.0-PREVIEW.agchannel-namespace-search.2024-06-12T1558.45bea490

Want to make another preview release?

Click 'Run workflow' in the GitHub UI, specifying the ag/channel-namespace-search branch, or use the GitHub CLI command:

gh workflow run release.yml --ref ag/channel-namespace-search

Want to make a full release after this PR is merged?

Click 'Run workflow' in the GitHub UI, leaving the branch as the default, or use the GitHub CLI command:

gh workflow run release.yml

[gu-scala-library-release]

@fredex42 has published a preview version of this PR with release workflow run #58, based on commit 5c27188:

30.0.0-PREVIEW.agchannel-namespace-search.2024-06-12T1606.5c271885

Want to make another preview release?

Click 'Run workflow' in the GitHub UI, specifying the ag/channel-namespace-search branch, or use the GitHub CLI command:

gh workflow run release.yml --ref ag/channel-namespace-search

Want to make a full release after this PR is merged?

Click 'Run workflow' in the GitHub UI, leaving the branch as the default, or use the GitHub CLI command:

gh workflow run release.yml

[JustinPinner]

All looks sensible to me 👍