Set file metadata block as optional #146

Tests ✅

Report	Passed	Time
tests/convert/result-junit-linux.xml	1✅	106ms
tests/convert/result-junit-mac.xml	1✅	128ms
tests/convert/result-junit-msvc.xml	1✅	150ms
tests/core/result-junit-linux.xml	1✅	3ms
tests/core/result-junit-mac.xml	1✅	5ms
tests/core/result-junit-msvc.xml	1✅	3ms

1 tests were completed in 106ms with 1 passed, 0 failed and 0 skipped.

Test suite	Passed	Failed	Skipped	Time
convert_tests	1✅			106ms

convert_tests.global
  ✅ Convert from ascii to binary

1 tests were completed in 128ms with 1 passed, 0 failed and 0 skipped.

Test suite	Passed	Failed	Skipped	Time
convert_tests	1✅			128ms

convert_tests.global
  ✅ Convert from ascii to binary

1 tests were completed in 150ms with 1 passed, 0 failed and 0 skipped.

Test suite	Passed	Failed	Skipped	Time
convert_tests.exe	1✅			150ms

convert_tests.exe.global
  ✅ Convert from ascii to binary

1 tests were completed in 3ms with 1 passed, 0 failed and 0 skipped.

Test suite	Passed	Failed	Skipped	Time
core_tests	1✅			3ms

core_tests.global
  ✅ Search for GCode blocks

1 tests were completed in 5ms with 1 passed, 0 failed and 0 skipped.

Test suite	Passed	Failed	Skipped	Time
core_tests	1✅			5ms

core_tests.global
  ✅ Search for GCode blocks

1 tests were completed in 3ms with 1 passed, 0 failed and 0 skipped.

Test suite	Passed	Failed	Skipped	Time
core_tests.exe	1✅			3ms

core_tests.exe.global
  ✅ Search for GCode blocks