feat: implement VariantMapper (#12)

[codecov[bot]]

Codecov Report

Patch coverage: 91.75% and project coverage change: +2.68 :tada:

Comparison is base (8593068) 80.94% compared to head (f1da91a) 83.63%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #13 +/- ## ========================================== + Coverage 80.94% 83.63% +2.68% ========================================== Files 16 17 +1 Lines 5175 6085 +910 ========================================== + Hits 4189 5089 +900 - Misses 986 996 +10 ``` | [Impacted Files](https://codecov.io/gh/bihealth/hgvs-rs/pull/13?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=bihealth) | Coverage Δ | | |---|---|---| | [src/data/interface.rs](https://codecov.io/gh/bihealth/hgvs-rs/pull/13?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=bihealth#diff-c3JjL2RhdGEvaW50ZXJmYWNlLnJz) | `100.00% <ø> (ø)` | | | [src/data/uta.rs](https://codecov.io/gh/bihealth/hgvs-rs/pull/13?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=bihealth#diff-c3JjL2RhdGEvdXRhLnJz) | `93.35% <0.00%> (-3.02%)` | :arrow_down: | | [src/data/uta\_sr.rs](https://codecov.io/gh/bihealth/hgvs-rs/pull/13?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=bihealth#diff-c3JjL2RhdGEvdXRhX3NyLnJz) | `50.60% <0.00%> (+6.15%)` | :arrow_up: | | [src/normalizer.rs](https://codecov.io/gh/bihealth/hgvs-rs/pull/13?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=bihealth#diff-c3JjL25vcm1hbGl6ZXIucnM=) | `67.86% <ø> (ø)` | | | [src/parser/ds.rs](https://codecov.io/gh/bihealth/hgvs-rs/pull/13?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=bihealth#diff-c3JjL3BhcnNlci9kcy5ycw==) | `62.77% <ø> (+2.22%)` | :arrow_up: | | [src/parser/impl\_parse.rs](https://codecov.io/gh/bihealth/hgvs-rs/pull/13?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=bihealth#diff-c3JjL3BhcnNlci9pbXBsX3BhcnNlLnJz) | `99.28% <0.00%> (-0.72%)` | :arrow_down: | | [src/mapper/altseq.rs](https://codecov.io/gh/bihealth/hgvs-rs/pull/13?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=bihealth#diff-c3JjL21hcHBlci9hbHRzZXEucnM=) | `90.43% <90.43%> (ø)` | | | [src/mapper/variant.rs](https://codecov.io/gh/bihealth/hgvs-rs/pull/13?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=bihealth#diff-c3JjL21hcHBlci92YXJpYW50LnJz) | `70.08% <90.72%> (+34.90%)` | :arrow_up: | | [src/sequences.rs](https://codecov.io/gh/bihealth/hgvs-rs/pull/13?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=bihealth#diff-c3JjL3NlcXVlbmNlcy5ycw==) | `99.50% <99.50%> (ø)` | | | [src/mapper/alignment.rs](https://codecov.io/gh/bihealth/hgvs-rs/pull/13?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=bihealth#diff-c3JjL21hcHBlci9hbGlnbm1lbnQucnM=) | `91.08% <100.00%> (-0.13%)` | :arrow_down: | | ... and [4 more](https://codecov.io/gh/bihealth/hgvs-rs/pull/13?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=bihealth) | | Help us with your feedback. Take ten seconds to tell us [how you rate us](https://about.codecov.io/nps?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=bihealth). Have a feature suggestion? [Share it here.](https://app.codecov.io/gh/feedback/?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=bihealth)

:umbrella: View full report at Codecov.
:loudspeaker: Do you have feedback about the report comment? Let us know in this issue.