Add diff-with-file option to copy command

[upsicleclown]

• Add ability to generate diff file by specifying --diff-with-file to the copy tool

[nyurik]

looks good, thanks! we do need some more testing though - a test that shows that all corner cases are handled as expected:

• same tile data
• a tile is added
• a tile is deleted

We may, as a separate PR, also want the mbtiles apply-diff src_file.mbtiles diff.mbtiles dst_file.mbtiles - but no rush on this

[nyurik]

P.S. There is a merge conflict - you may want to simply delete and re-create the lock file after you fix the cargo.toml file merge.

[upsicleclown]

looks good, thanks! we do need some more testing though - a test that shows that all corner cases are handled as expected:

• same tile data
• a tile is added
• a tile is deleted

@nyurik all of these test cases are addressed by diffing geography-class-jpg.mbtiles against the new file I created called geography-class-jpg-modified.mbtiles.

geography-class-jpg-modified.mbtiles has 1 row added, 1 row removed and 1 row modified. This is why I assert that the diff has 3 tiles rows. I do realize this assert_eq!(...,3) isn't very clear, but I'm not sure how to make it more transparent while also not making it needlessly complex.

[upsicleclown]

The failing test is caused by the fact that the CI pipeline doesn't install sqlite. Sqlite is needed with these changes to be able to run the corresponding integration tests in test.sh. However, I have an upcoming change that makes it so that installing sqlite is not needed anyways: upsicleclown#2.
So I would prefer merging those changes into this branch and then merging this branch, so that I do not have to make a fix and then inevitably undo it.

[nyurik]

agree, lets comment out the apply test in the test.sh for now. Eventually i would still like to have it as part of the test suite - this way our documentation always stays correct (i.e. we can always guarantee that we can apply the delta directly with sqlite3)

[nyurik]

looks good, one minor nit (in addition to commenting out the call to sqlite3). BTW, you may want to add a "TODO: " comment - to only re-enable it once sqlite3 is installed on windows CI (and possibly mac?)

[nyurik]

p.s. feel free to merge it once it passes the ci