Feature/#28 optionally enfore relationship type by test meta

[datnguye]

resolves #28

Description

• Cover relationship type by test meta config
• Default to many-to-one if not specified

Checklist

• I have read the contributing guide and understand what's expected of me
• I have run this code in development and it appears to resolve the stated issue
• This PR includes tests, or tests are not required/relevant for this PR
• I have opened an issue to add/update docs, or docs changes are not required/relevant for this PR

[codecov]

Codecov Report

Merging #32 (18dee09) into main (3fe00f3) will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##              main       #32   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           35        35           
  Lines          730       788   +58     
=========================================
+ Hits           730       788   +58     

Impacted Files	Coverage Δ
dbterd/adapters/algos/meta.py	100.00% <100.00%> (ø)
dbterd/adapters/algos/test_relationship.py	100.00% <100.00%> (ø)
...rd/adapters/targets/dbml/dbml_test_relationship.py	100.00% <100.00%> (ø)
...pters/targets/mermaid/mermaid_test_relationship.py	100.00% <100.00%> (ø)
...ers/targets/plantuml/plantuml_test_relationship.py	100.00% <100.00%> (ø)
dbterd/constants.py	100.00% <100.00%> (ø)
...ests/unit/adapters/algos/test_test_relationship.py	100.00% <100.00%> (ø)
...apters/targets/dbml/test_dbml_test_relationship.py	100.00% <100.00%> (ø)
.../targets/mermaid/test_mermaid_test_relationship.py	100.00% <100.00%> (ø)
...argets/plantuml/test_plantuml_test_relationship.py	100.00% <100.00%> (ø)