feat: decode text

[ghost]

• Added IOBuffer.decodeText
• It should be equivalent to IOBuffer.readUtf8 when no encoding is given (or when utf-8 is given)

Probably needs adjustments.

I am not sure what is the problem with Node 12x. If the tsconfig.target is changed to 2019, and run nvm use 12 a different error appears:

src/__tests__/write.ts:95:27 - error TS2737: BigInt literals are not available when targeting lower than ES2020.
95     buffer.writeBigUint64(1234567890n);

[codecov[bot]]

Codecov Report

Base: 100.00% // Head: 100.00% // No change to project coverage :thumbsup:

Coverage data is based on head (df44995) compared to base (49a2df9). Patch coverage: 100.00% of modified lines in pull request are covered.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #55 +/- ## ========================================= Coverage 100.00% 100.00% ========================================= Files 2 2 Lines 223 225 +2 Branches 20 22 +2 ========================================= + Hits 223 225 +2 ``` | [Impacted Files](https://codecov.io/gh/image-js/iobuffer/pull/55?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=image-js) | Coverage Δ | | |---|---|---| | [src/IOBuffer.ts](https://codecov.io/gh/image-js/iobuffer/pull/55/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=image-js#diff-c3JjL0lPQnVmZmVyLnRz) | `100.00% <100.00%> (ø)` | | | [src/text.ts](https://codecov.io/gh/image-js/iobuffer/pull/55/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=image-js#diff-c3JjL3RleHQudHM=) | `100.00% <100.00%> (ø)` | | 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=image-js). 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=image-js)

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

[targos]

We don't need to support Node.js 12 anymore. Can you please update the workflow at https://github.com/image-js/iobuffer/blob/main/.github/workflows/nodejs.yml#L32 to remove 12.x and add 18.x.

[ghost]

I see. Yes, I'll do in a sec. Done @targos.