pgsql: Add PostgresVersion.pm method to emit the major version string

Add PostgresVersion.pm method to emit the major version string

For versions before 10, this will produce dotted notation unless a
separator argument is given, in which case it is used.

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/1e8d89f8800e0aaafc66e87e8e5fedf5dbd038cf

Modified Files
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src/test/perl/PostgresVersion.pm | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)