Remove UBSAN workaround related to `charset_converter`

[Flamefire]

To avoid the UBSAN failure it is enough to mark the class as VISIBLE similar to e.g. exception types. This allows to remove the workaround with custom deleter and UBSAN-supression macros which makes the code more readable

[codecov[bot]]

Codecov Report

Merging #186 (23e7967) into develop (d50fc59) will decrease coverage by 0.01%. The diff coverage is 100.00%.

Additional details and impacted files

[](https://app.codecov.io/gh/boostorg/locale/pull/186?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=boostorg) ```diff @@ Coverage Diff @@ ## develop #186 +/- ## =========================================== - Coverage 92.79% 92.79% -0.01% =========================================== Files 112 112 Lines 9897 9891 -6 =========================================== - Hits 9184 9178 -6 Misses 713 713 ``` | [Impacted Files](https://app.codecov.io/gh/boostorg/locale/pull/186?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=boostorg) | Coverage Δ | | |---|---|---| | [src/boost/locale/encoding/codepage.cpp](https://app.codecov.io/gh/boostorg/locale/pull/186?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=boostorg#diff-c3JjL2Jvb3N0L2xvY2FsZS9lbmNvZGluZy9jb2RlcGFnZS5jcHA=) | `97.53% <ø> (ø)` | | | [test/test\_encoding.cpp](https://app.codecov.io/gh/boostorg/locale/pull/186?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=boostorg#diff-dGVzdC90ZXN0X2VuY29kaW5nLmNwcA==) | `97.49% <ø> (ø)` | | | [include/boost/locale/detail/encoding.hpp](https://app.codecov.io/gh/boostorg/locale/pull/186?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=boostorg#diff-aW5jbHVkZS9ib29zdC9sb2NhbGUvZGV0YWlsL2VuY29kaW5nLmhwcA==) | `100.00% <100.00%> (ø)` | | | [include/boost/locale/encoding.hpp](https://app.codecov.io/gh/boostorg/locale/pull/186?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=boostorg#diff-aW5jbHVkZS9ib29zdC9sb2NhbGUvZW5jb2RpbmcuaHBw) | `100.00% <100.00%> (ø)` | | ... and [1 file with indirect coverage changes](https://app.codecov.io/gh/boostorg/locale/pull/186/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=boostorg) ------ [Continue to review full report in Codecov by Sentry](https://app.codecov.io/gh/boostorg/locale/pull/186?src=pr&el=continue&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=boostorg). > **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=boostorg) > `Δ = absolute (impact)`, `ø = not affected`, `? = missing data` > Powered by [Codecov](https://app.codecov.io/gh/boostorg/locale/pull/186?src=pr&el=footer&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=boostorg). Last update [d50fc59...23e7967](https://app.codecov.io/gh/boostorg/locale/pull/186?src=pr&el=lastupdated&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=boostorg). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=boostorg).