Increase test coverage (90%)

[aelsayed95]

For https://github.com/bloomberg/memray/issues/351

Describe your changes

• Adds integration tests for tree, stats and summary commands
• Adds unit tests for the stats command
• Raises minimum required coverage to --cov-fail-under=90

Testing performed Ran tests and make pycoverage: the above commands are now at 100% coverage (but not the related reporters).

Total coverage: 93%

``` ---------- coverage: platform linux, python 3.10.11-final-0 ---------- Name Stmts Miss Branch BrPart Cover Missing ------------------------------------------------------------------------------------------------ src/memray/__main__.py 4 0 2 1 83% 5->exit src/memray/_ipython/flamegraph.py 65 3 14 3 92% 102, 131, 138 src/memray/commands/attach.py 160 69 64 12 50% 97->103, 101, 106-108, 119->123, 128-156, 161-163, 178-185, 188-190, 205-206, 209-219, 301-306, 311, 325-326, 343, 353, 367-383 src/memray/commands/common.py 93 9 26 5 88% 14, 36, 47, 53, 63, 130->133, 134-143 src/memray/commands/live.py 43 8 22 5 74% 91, 96->100, 110, 112, 115-119 src/memray/commands/run.py 155 15 62 9 88% 46, 82-93, 98->100, 101, 122-124, 127-129, 137, 139->142, 181, 307, 314, 317 src/memray/commands/transform.py 39 3 12 5 84% 37, 46->exit, 53, 55, 64->72 src/memray/reporters/flamegraph.py 123 7 36 8 89% 110-113, 120->122, 122->125, 159->161, 161->164, 170, 189->192, 205, 232 src/memray/reporters/stats.py 95 2 41 2 97% 89, 135 src/memray/reporters/table.py 33 1 6 1 95% 67 src/memray/reporters/transform.py 52 1 14 1 97% 82 src/memray/reporters/tui.py 235 2 62 1 99% 58, 374 tests/integration/misbehaving_extension/setup.py 10 10 2 0 0% 1-12 tests/integration/multithreaded_extension/main.py 8 8 2 0 0% 1-13 tests/integration/multithreaded_extension/setup.py 10 10 2 0 0% 1-12 tests/integration/test_api.py 54 4 30 4 90% 73, 86, 93, 105 tests/integration/test_attach.py 36 6 10 2 78% 58, 90-96, 100->exit tests/integration/test_extensions.py 169 3 46 0 99% 81-83 tests/integration/test_main.py 450 36 38 7 91% 85-86, 94-103, 537->543, 1132-1137, 1251-1254, 1258-1261, 1268->exit, 1293-1296, 1306->exit, 1328-1329, 1356-1358, 1366->exit, 1390-1392, 1473 tests/integration/test_native_tracking.py 263 4 100 2 98% 247->254, 300-303 tests/integration/test_processes.py 99 70 38 0 21% 27-30, 34-36, 42-74, 80-130, 136-161, 171-185 tests/integration/test_socket.py 159 5 42 1 97% 136-139, 232 tests/integration/test_tracing.py 529 2 174 4 99% 294, 999->exit, 1008->exit, 1022, 1036->exit, 1049->exit tests/integration/test_tracking.py 881 21 328 13 97% 79->77, 83, 138->136, 142, 176->174, 180, 220-221, 393->391, 397, 1484, 1542-1558, 1647->exit, 1668->exit tests/unit/test_reader.py 42 1 16 0 98% 64 tests/unit/test_stats_reporter.py 74 21 18 0 66% 22-62 tests/unit/test_tracker.py 18 2 12 2 87% 18, 33 tests/utils.py 72 17 26 2 72% 33-47, 81, 86, 96-100 ------------------------------------------------------------------------------------------------ TOTAL 6511 340 1582 90 93% 33 files skipped due to complete coverage. Required test coverage of 90% reached. Total coverage: 93.33% ======================== 542 passed in 85.08s (0:01:25) ======================== ```

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