Fix issue with truncation of result of arithmetic computations to correct scale when result is of numeric datatype

[rohit01010]

Description

Currently, whenever an arithmetic operation is performed which results in numeric/decimal, we are storing the result till maximum possible scale instead of the correct scale. This is causing incorrect results in some arithmetic operations such as numeric division, numeric multiplication etc. This PR will fix this issue by adding a hooks in engine which truncates the result value to the correct scale and also sets the correct typmod of multiple nodes whose base type is NUMERIC.

Engine PR: babelfish-for-postgresql/postgresql_modified_for_babelfish#529

Issues Resolved

BABEL-5467

Test Scenarios Covered

• Use case based -

• Boundary conditions -

• Arbitrary inputs -

• Negative test cases -

• Minor version upgrade tests -

• Major version upgrade tests -

• Performance tests -

• Tooling impact -

• Client tests -

Check List

• Commits are signed per the DCO using --signoff

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[coveralls]

Pull Request Test Coverage Report for Build 13696974677

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
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• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

Details

• 143 of 178 (80.34%) changed or added relevant lines in 3 files are covered.
• 277 unchanged lines in 2 files lost coverage.
• Overall coverage increased (+0.05%) to 75.058%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
contrib/babelfishpg_tsql/src/hooks.c	49	53	92.45%
contrib/babelfishpg_tds/src/backend/tds/tdsresponse.c	93	124	75.0%

Files with Coverage Reduction	New Missed Lines	%
contrib/babelfishpg_common/src/varchar.c	19	85.15%
contrib/babelfishpg_tsql/src/pltsql_ruleutils.c	258	61.37%

Totals
Change from base Build 13569814182:	0.05%
Covered Lines:	47279
Relevant Lines:	62990

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💛 - Coveralls

[KushaalShroff]

Reusing the same piece of code everywhere, chance of encapsulating it?