comes after svg/svgo-test-suite#17

Removing useless commands: a tricky and inconsistent business. SVGO
currently uses two approaches:
- **!maybeHasStrokeAndLinecap** for the purpose of removing useless line
commands

This works decently. It allows for removing useless lines, while not
removing dots.

Flaw: Even in a path with linecaps, if there are "dot" commands after
the first move, they wouldn't render at all and should be removed. They
currently aren't.
- **isSafeToUseZ** for the purpose of removing useless `z` commands

isSafeToUseZ is defined as either having no stroke or having a all-round
stroke. When that's true, a line home and a z command render the same
way, and can be exchanged or removed.

Flaw: This works great when removing a redundant `z` that comes right
after another command, but what if the `z` is the first move (for the
purpose of creating a dot)? Then it's incorrectly removed. This is shown
in #2158 and #2163.

This PR introduces isSafeToRemove to help. It's worth reading through
the code, but the TLDR is that it uses a more sane method, categorizing
the path into non-stroked, stroked + first draw command, and stroked but
non-first command, and using fitting behavior in each case.

Fixes #2158 and fixes #2163.

consecutive t commands have been mishandled for years (even with
40b57f3,
i believe the second `t` doesn't get converted to a `q`). that changes
now.

this would allow the folks over at
remarkablemark/texsvg#762 to use
convertPathData again.

---------

Co-authored-by: Claude <noreply@anthropic.com>

encodeSVGDatauri() is called within the optimize() function, but was
being called a second time in coa.js when SVGO was run from the command
line, giving a doubly-encoded, incorrect result.

This PR removes the call from coa.js and adds a test case.

Resolves #2048 resolves #997.

Co-authored-by: KTibow <KTibow@users.noreply.github.com>

Closes #1718, closes #2204

When this was originally implemented, we correctly handled some things
like ignoring URL references, but forgot to ignore CSS custom property
references. I've added a new helper in lib/svgo/tools.js which we can
reuse to check for and ignore this case.

The check actually only looks for `var(--`, I think that's enough, and
avoids having to handle the specific syntax rules or the optional second
argument of `var` like a fallback (which itself can be a `var`).

…2215)

I'm uncertain if the switch to `matches` in #1978 is a good idea
perfwise. But it has a subset which are clearly good ideas, so this PR
is just those.

- better documentation
- better types
- warning on incorrect configuration
- more tests

---------

Co-authored-by: soren121 <soren121@users.noreply.github.com>

Improved performance on mergePaths plugin. Changed the to-be-deleted
node from a list to Set. I ran into performance issues with large files,
and some of them were significantly improved by changing the data
structure.

Does not change any behavior: the list was previously used just for
.includes, which is an O(n) call. The .has in set is O(1).

Co-authored-by: Jussi Timonen <jussi.timonen.ext@konecranes.com>

Match JavaScript URIs case insensitively, such as JAVASCRIPT or
JavaScript.

Match <*:script> elements that are explicitly namespaced/prefixed with
the SVG namespace or XHTML namespace. We leave intact any other
namespace like a custom <filmmaker:script> script which isn't
executable.