[Core] Singular data tests can now be documented

[FishtownBuildBot]

At a minimum, update body to include a link to the page on docs.getdbt.com requiring updates and what part(s) of the page you would like to see updated.
Originating from this issue: dbt-labs/dbt-core#9005
Original pull request: dbt-labs/dbt-core#10744
New pull request: dbt-labs/dbt-core#10792

Page(s) to update

• https://docs.getdbt.com/reference/resource-properties/description (add new "Data tests" tab)
• https://docs.getdbt.com/docs/build/data-tests (maybe 🤷)
• https://docs.getdbt.com/reference/project-configs/docs-paths (since it now includes test-paths)

Code examples

tests/my_singular_test.sql

with my_cte as (
    select 1 as id, 'foo' as name
    union all
    select 2 as id, 'bar' as name
)
select * from my_cte

Without docs blocks

tests/_properties.yml

data_tests:
  - name: my_singular_test
    description: Some docs
    config:
      error_if: ">10"
    meta:
      some_key: some_val

With docs blocks

Or with docs blocks:

tests/example.md

{% docs my_singular_test_documentation %}
Some docs from a doc block
{% enddocs %}

tests/_properties.yml

data_tests:
  - name: my_singular_test
    description: "{{ doc('my_singular_test_documentation') }}"
    config:
      error_if: ">10"
    meta:
      some_key: some_val

List 'em and run 'em

List 'em:

$ dbt list --resource-type test -q 

my_project.my_singular_test

Run 'em:

$ dbt test -s my_project.my_singular_test

19:55:23  Running with dbt=1.9.0-a1
19:55:23  Registered adapter: postgres=1.9.0-a1
19:55:23  Found 1 test, 423 macros
19:55:23  
19:55:23  Concurrency: 5 threads (target='postgres')
19:55:23  
19:55:24  1 of 1 START test my_singular_test ............................................. [RUN]
19:55:24  1 of 1 FAIL 2 my_singular_test ................................................. [FAIL 2 in 0.10s]
19:55:24  
19:55:24  Finished running 1 test in 0 hours 0 minutes and 1.13 seconds (1.13s).
19:55:24  
19:55:24  Completed with 1 error, 0 partial successs, and 0 warnings:
19:55:24  
19:55:24  Failure in test my_singular_test (tests/my_singular_test.sql)
19:55:24    Got 2 results, configured to fail if != 0
19:55:24  
19:55:24    compiled code at target/compiled/my_project/tests/my_singular_test.sql
19:55:24  
19:55:24  Done. PASS=0 WARN=0 ERROR=1 SKIP=0 TOTAL=1