tests: reproduce the nullrev bug in an end-to-end test

rust-config: fix incorrect coercion of null values to false As explained in the previous changeset: Probably being too trigger happy about boolean values, I incorrectly set the transform for a `None` to a `Some(false)`. It would cause for example the `ui.formatted` value to be set to `Some(false)`, which turns off the colors among other things, when `None` would trigger the automatic behavior.

rust-config: show default `null` is coerced incorrectly to `false` Probably being too trigger happy about boolean values, I incorrectly set the transform for a `None` to a `Some(false)`. It would cause for example the `ui.formatted` value to be set to `Some(false)`, which turns off the colors among other things, when `None` would trigger the automatic behavior. This is fixed in the next commit.

rust-config: fix fallback to default not parsing the default value When a config item's default is a string, it sometimes needs to be parsed into another type, like in the case of `cmdserver.max-log-size`, that returns a number of bytes from a human-readable amount like `25MB`. The logic for the fix is explained inline.

rust-config: demonstrate a bug when falling back to non-trivial default values The default value (when the user hasn't configured anything) is not run through the value parser, causing a programming error to happen because of type mismatch. This will be fixed in the next commit.

rust: make `Revision` a newtype This change is the one we've been building towards during this series. The aim is to make `Revision` mean more than a simple integer, holding the information that it is valid for a given revlog index. While this still allows for programmer error, since creating a revision directly and querying a different index with a "checked" revision are still possible, the friction created by the newtype will hopefully make us think twice about which type to use. Enough of the Rust ecosystem relies on the newtype pattern to be efficiently optimized away (even compiler in codegen tests¹), so I'm not worried about this being a fundamental problem. [1] https://github.com/rust-lang/rust/blob/7a70647f195f6b0a0f1ebd72b1542ba91a32f43a/tests/codegen/vec-in-place.rs#L47

rust: implement the `Graph` trait for all revlogs This is trivial and makes all the algorithms relying on the trait usable for more use cases.

rust: use the new `UncheckedRevision` everywhere applicable This step converts all revisions that shouldn't be considered "valid" in any context to `UncheckedRevison`, allowing `Revision` to be changed for a stronger type in a later changeset. Note that the conversion from unchecked to checked is manual and requires at least some thought from the programmer, although directly using `Revision` is still possible. A later changeset will make this mistake harder to make.

rust-revlog: split logic for `rawdata` to prepare for `UncheckedRevision` use In the next changeset, we will change the logic to use `UncheckedRevision` in the non-general delta case. The general delta case will use the "checked" path since `base_rev_or_base_of_delta_chain` will be checked.

rust: remove unused error variant All paths check that the working directory revision is not used.

rust: add `UncheckedRevision` type This is the start of a series whose aim is to separate "checked" and "unchecked" revision numbers. A "checked" revision number is valid for a given index, allowing us to have faster algorithms that don't do redundant checks all the time and have a clearer view of the kinds of revisions we're working with.

debugwireproto: migrate `opts` to native kwargs

debugwireargs: migrate `opts` to native kwargs

debugwalk: migrate `opts` to native kwargs

debug_revlog_stats: migrate `opts` to native kwargs

debugbackupbundle: migrate `opts` to native kwargs

debugsidedata: migrate `opts` to native kwargs

debugserve: migrate `opts` to native kwargs

debugrevspec: migrate `opts` to native kwargs

debugrevlogindex: migrate `opts` to native kwargs

debugrevlog: migrate `opts` to native kwargs

debugrename: migrate `opts` to native kwargs

debugrebuildfncache: migrate `opts` to native kwargs

debugpickmergetool: migrate `opts` to native kwargs

debugp2copies: migrate `opts` to native kwargs

debugp1copies: migrate `opts` to native kwargs

debugobsolete: migrate `opts` to native kwargs

debugmergestate: migrate `opts` to native kwargs

debugknown: migrate `opts` to native kwargs

debuginstall: migrate `opts` to native kwargs