Replace Moment.js with Day.js

[Danieladu]

Fixes #3133

Description

For Moment.js is now in legacy/maintenance mode. Consider replacing it with other libraries.
There are several other alternatives. Including luxon, Day.js and date-fns

Why we choose Day.js. There are several considerations:

• Small. It only 2.9K in size (without extension).
• API is highly compatible with Moment.js. So, it is easy for SDK to convert.
• Great support for internationalization.
• Rich and comprehensive functions and extensions.

Detailed introduction and comparison：https://github.com/you-dont-need/You-Dont-Need-Momentjs/blob/master/README.md

Affected projects

• libraries/adaptive-expressions
• libraries/botbuilder-repo-utils
• libraries/botbuilder
• tools

Change details

• Drop moment and moment-timezone dependency, and use dayjs instead
• Use native Date functions as much as possible to implement related functions
• Make date related function purer
• Remove some unnecessary intermediate functions

[coveralls]

Pull Request Test Coverage Report for Build 500047203

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 58 unchanged lines in 11 files lost coverage.
• Overall coverage increased (+1.3%) to 84.646%

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Files with Coverage Reduction	New Missed Lines	%
libraries/adaptive-expressions/src/builtinFunctions/addToTime.ts	1	88.57%
libraries/adaptive-expressions/src/builtinFunctions/getNextViableDate.ts	1	95.18%
libraries/adaptive-expressions/src/builtinFunctions/getPreviousViableTime.ts	1	92.86%
libraries/adaptive-expressions/src/builtinFunctions/startOfDay.ts	1	87.1%
libraries/adaptive-expressions/src/builtinFunctions/startOfHour.ts	1	87.1%
libraries/adaptive-expressions/src/builtinFunctions/startOfMonth.ts	1	87.1%
libraries/adaptive-expressions/src/builtinFunctions/convertFromUTC.ts	2	90.48%
libraries/adaptive-expressions/src/builtinFunctions/getNextViableTime.ts	2	90.28%
libraries/adaptive-expressions/src/builtinFunctions/getPreviousViableDate.ts	2	92.77%
libraries/adaptive-expressions/src/functionUtils.internal.ts	5	96.09%

Totals
Change from base Build 500034910:	1.3%
Covered Lines:	17836
Relevant Lines:	20132

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💛 - Coveralls

[joshgummersall]

This is awesome! What a huge bundle size saving 👍

[joshgummersall]

Couple quick suggestions, otherwise looks good!