Add IFS function (Issue 1157)

[thilgen]

Context

Add support for the IFS function - a standard formula provided by

• Google Sheets (documentation)
• MS Excel (documentation)
• Open Document Format for Office Applications (NOT SUPPORTED)

For more information

• Issue Writeup: Function IFS #1157

How did you test your changes?

npm run test
> TOTAL: 9564 SUCCESS

npm run lint
> 0 errors and 2043 warnings potentially fixable with the `--fix` option.

npm run test:coverage

--------------------|---------|----------|---------|---------|---------------------
File                | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s   
--------------------|---------|----------|---------|---------|---------------------
BooleanPlugin.ts    |     100 |      100 |     100 |     100 |                     

Types of changes

• Breaking change (a fix or a feature because of which an existing functionality doesn't work as expected anymore)
• New feature or improvement (a non-breaking change that adds functionality)
• Bug fix (a non-breaking change that fixes an issue)
• Additional language file, or a change to an existing language file (translations)
• Change to the documentation

Related issues:

1. Fixes Function IFS #1157

Checklist:

• I have reviewed the guidelines about Contributing to HyperFormula and I confirm that my code follows the code style of this project.
• I have signed the Contributor License Agreement.
• [N/A] My change is compliant with the OpenDocument standard.
• My change is compatible with Microsoft Excel.
• My change is compatible with Google Sheets.
• I described my changes in the CHANGELOG.md file.
• My changes require a documentation update.
• My changes require a migration guide.

[AMBudnik]

Thank you for sharing a pull request with a new function. We'll review it as soon as possible.

[codecov]

Codecov Report

Merging #1270 (c29de49) into develop (6911728) will increase coverage by 0.01%.
The diff coverage is 100.00%.

@@             Coverage Diff             @@
##           develop    #1270      +/-   ##
===========================================
+ Coverage    97.19%   97.20%   +0.01%     
===========================================
  Files          166      167       +1     
  Lines        14243    14297      +54     
  Branches      2966     2988      +22     
===========================================
+ Hits         13843    13897      +54     
  Misses         400      400              

Impacted Files	Coverage Δ
src/i18n/languages/csCZ.ts	100.00% <ø> (ø)
src/i18n/languages/daDK.ts	100.00% <ø> (ø)
src/i18n/languages/deDE.ts	100.00% <ø> (ø)
src/i18n/languages/enGB.ts	100.00% <ø> (ø)
src/i18n/languages/esES.ts	100.00% <ø> (ø)
src/i18n/languages/fiFI.ts	100.00% <ø> (ø)
src/i18n/languages/frFR.ts	100.00% <ø> (ø)
src/i18n/languages/huHU.ts	100.00% <ø> (ø)
src/i18n/languages/itIT.ts	100.00% <ø> (ø)
src/i18n/languages/nbNO.ts	100.00% <ø> (ø)
... and 10 more

[sequba]

Thank you @thilgen. I'll merge it to a feature branch first to make a few minor adjustments ;)