Deprecate binary, trinary, octal, and hexadecimal in favor of new all-your-base exercise

We've settled on replacing the four almost identical exercises with one that is more interesting and comprehensive, which converts a number in an arbitrary base to the equivalent in a second arbitrary base. See https://github.com/exercism/x-common/issues/276 for details.

We need to (I think):
- [x] wait for the pull request that adds `all-your-base` to be accepted
- [x] finish working out the process for deprecating exercises in https://github.com/exercism/discussions/issues/40
- [x] add a `.deprecated` file to octal
- [x] add a `.deprecated` file to hexadecimal
- [x] add a `.deprecated` file to binary
- [x] add a `.deprecated` file to trinary
- [ ] draft the text for a new issue that can be submitted to all the languages (see https://github.com/exercism/blazon#tips)
- [ ] submit the issue using blazon
- [ ] wait for all the related issues to be closed
- [ ] close this issue