Remove constraints on Code Overflow column from xxxSearchParam tables

[rajithaalurims]

Description

Removed constraints on Code and Code Overflow columns from xxxSearchParam tables.

Related issues

Addresses [issue #160420].

Testing

Manually verified the scenario by testing with same data that is breaking before the change
Existing unit and E2E tests

FHIR Team Checklist

• Update the title of the PR to be succinct and less than 65 characters
• Add a milestone to the PR for the sprint that it is merged (i.e. add S47)
• Tag the PR with the type of update: Bug, Build, Dependencies, Enhancement, New-Feature or Documentation
• Tag the PR with Open source, Azure API for FHIR (CosmosDB or common code) or Azure Healthcare APIs (SQL or common code) to specify where this change is intended to be released.
• Tag the PR with Schema Version backward compatible or Schema Version backward incompatible or Schema Version unchanged if this adds or updates Sql script which is/is not backward compatible with the code.
• When changing or adding behavior, if your code modifies the system design or changes design assumptions, please create and include an ADR.
• CI is green before merge
• Review squash-merge requirements

Semver Change (docs)

Patch|Skip|Feature|Breaking (reason)

[SergeyGaluzo]

We use len() in check constraints on other tables. Should we fix these too?

[SergeyGaluzo]

With addition of delayed writes to search param tables all checks must be performed on input table variables to MergeResources stored procedure. Please add.

[paorodma-ms]

Should we rename the PR to something more in line with the actual changes?