tables: Add constraints and testing

[directionless]

After #6103 I thought I'd take a pass at the spec files and tests. Not totally sure on all of these.

Also adds an IntOrEmpty type to the validation map

Requires: #6104

Relates To: #5932

[theopolis]

85: [----------] 1 test from processOpenSockets
85: [ RUN      ] processOpenSockets.test_sanity
85: /__w/1/s/usr/src/debug/osquery/tests/integration/tables/helper.cpp:162: Failure
85: Expected: (validation_map.count(rec.first)) != (std::size_t{0}), actual: 0 vs 0
85: Unexpected column "net_namespace" in a row
85: /__w/1/s/usr/src/debug/osquery/tests/integration/tables/helper.cpp:162: Failure
85: Expected: (validation_map.count(rec.first)) != (std::size_t{0}), actual: 0 vs 0
85: Unexpected column "net_namespace" in a row
85: /__w/1/s/usr/src/debug/osquery/tests/integration/tables/helper.cpp:162: Failure
85: Expected: (validation_map.count(rec.first)) != (std::size_t{0}), actual: 0 vs 0
85: Unexpected column "net_namespace" in a row
85: /__w/1/s/usr/src/debug/osquery/tests/integration/tables/helper.cpp:162: Failure
85: Expected: (validation_map.count(rec.first)) != (std::size_t{0}), actual: 0 vs 0
85: Unexpected column "net_namespace" in a row
85: /__w/1/s/usr/src/debug/osquery/tests/integration/tables/helper.cpp:162: Failure
85: Expected: (validation_map.count(rec.first)) != (std::size_t{0}), actual: 0 vs 0
85: Unexpected column "net_namespace" in a row
85: /__w/1/s/usr/src/debug/osquery/tests/integration/tables/helper.cpp:162: Failure
85: Expected: (validation_map.count(rec.first)) != (std::size_t{0}), actual: 0 vs 0
85: Unexpected column "net_namespace" in a row
85: /__w/1/s/usr/src/debug/osquery/tests/integration/tables/helper.cpp:162: Failure
85: Expected: (validation_map.count(rec.first)) != (std::size_t{0}), actual: 0 vs 0
85: Unexpected column "net_namespace" in a row
85: /__w/1/s/usr/src/debug/osquery/tests/integration/tables/helper.cpp:162: Failure
85: Expected: (validation_map.count(rec.first)) != (std::size_t{0}), actual: 0 vs 0
85: Unexpected column "net_namespace" in a row
85: /__w/1/s/usr/src/debug/osquery/tests/integration/tables/helper.cpp:162: Failure
85: Expected: (validation_map.count(rec.first)) != (std::size_t{0}), actual: 0 vs 0
85: Unexpected column "net_namespace" in a row
85: /__w/1/s/usr/src/debug/osquery/tests/integration/tables/helper.cpp:162: Failure
85: Expected: (validation_map.count(rec.first)) != (std::size_t{0}), actual: 0 vs 0
85: Unexpected column "net_namespace" in a row
85: /__w/1/s/usr/src/debug/osquery/tests/integration/tables/helper.cpp:162: Failure
85: Expected: (validation_map.count(rec.first)) != (std::size_t{0}), actual: 0 vs 0
85: Unexpected column "net_namespace" in a row
85: /__w/1/s/usr/src/debug/osquery/tests/integration/tables/helper.cpp:162: Failure
85: Expected: (validation_map.count(rec.first)) != (std::size_t{0}), actual: 0 vs 0
85: Unexpected column "net_namespace" in a row
85: /__w/1/s/usr/src/debug/osquery/tests/integration/tables/helper.cpp:162: Failure
85: Expected: (validation_map.count(rec.first)) != (std::size_t{0}), actual: 0 vs 0
85: Unexpected column "net_namespace" in a row
85: /__w/1/s/usr/src/debug/osquery/tests/integration/tables/helper.cpp:162: Failure
85: Expected: (validation_map.count(rec.first)) != (std::size_t{0}), actual: 0 vs 0
85: Unexpected column "net_namespace" in a row
85: /__w/1/s/usr/src/debug/osquery/tests/integration/tables/helper.cpp:162: Failure
85: Expected: (validation_map.count(rec.first)) != (std::size_t{0}), actual: 0 vs 0
85: Unexpected column "net_namespace" in a row
85: /__w/1/s/usr/src/debug/osquery/tests/integration/tables/helper.cpp:162: Failure
85: Expected: (validation_map.count(rec.first)) != (std::size_t{0}), actual: 0 vs 0
85: Unexpected column "net_namespace" in a row
85: [  FAILED  ] processOpenSockets.test_sanity (10 ms)
85: [----------] 1 test from processOpenSockets (10 ms total)

85: [----------] 1 test from pythonPackages
85: [ RUN      ] pythonPackages.test_sanity
85: /__w/1/s/usr/src/debug/osquery/tests/integration/tables/python_packages.cpp:36: Failure
85: Value of: data.empty()
85:   Actual: true
85: Expected: false
85: [  FAILED  ] pythonPackages.test_sanity (1 ms)
85: [----------] 1 test from pythonPackages (1 ms total)