V2: improve data-structure modification functions

[sr9000]

What had be done:

• reorganize data-structure modification functions into separate sub-packages
• using same rules for functions naming across all sub-packages
• using generator for repetative function templates

brief overview of a packages

1. loany - funcs that operate on any or converts from/to []any or map[K]any
2. lofn - functional-style helpers, especially Partial ones (https://en.wikipedia.org/wiki/Partial_application)
3. lomap - non-destructive operations on maps
4. loset - specialisation of map that uses only keys map[K]struct{}
5. loslice - non-destructive operations on slices
6. lotup - heavily code-generated sub-package to operate with Tuple<N>
7. lotype - tiny sub-package to have lambda-caster on ints/strings.
8. mutmap - destructive operations on maps
9. mutslice - destructive operations on slices

this PR is draft only and a lot of work is waiting (especially tests) and before to adopt that changes some questions must be answered:

1. is this PR ever can be approved or separate package is preferable?
2. is this PR become version 2 or changes can be live along with original functions?

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📨 For a quick response, contact me on Telegram: @bsr9000.

[sr9000]

@samber Hi! I'm looking for the best way to delivery suggested improvements into lodash codebase 🚀

What can I do to make it possible?