catch missing delimiters when building connection strings

[TimHess]

Description

Handle cases where a user-provided connection string does not end with the delimiter and other settings are appended

Addresses #1076 in release/3.2 - A similar fix needs to happen for 4.0 but for that release we can choose to only prepend the delimiter instead of appending

Quality checklist

• Your code complies with our Coding Style.
• You've updated unit and/or integration tests for your change, where applicable.
• You've updated documentation for your change, where applicable.
  If your change affects other repositories, such as Documentation, Samples and/or MainSite, add linked PRs here.
• There's an open issue for the PR that you are making. If you'd like to propose a new feature or change, please open an issue to discuss the change or find an existing issue.
• You've added required license files and/or file headers (explaining where the code came from with proper attribution), where code is copied from StackOverflow, a blog, or OSS.

[TimHess]

/azp run Steeltoe.All

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

100.0% Coverage
0.0% Duplication

[hananiel]

LGTM;

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).