Support Tact 1.2.0

[anton-trunov]

Here is the link to Tact 1.2.0 changelog: https://github.com/tact-lang/tact/blob/main/CHANGELOG.md#120---2024-02-29.

The relevant features or changes are these:

• [ ] Added augmented assignment operators: +=, -=, *=, /=and %=
• [ ] Decimal and hexadecimal literals now allow underscores as numerical separators, e.g. 1_000_000_000
• [ ] Added binary and octal literals with underscores as numerical separators
• [ ] Added ternary conditional operator condition ? then : else
• [ ] Added the new SendBounceIfActionFail send mode constant to the standard library