feat(ottl): add Bool function

[danelson]

Description

Adds a Bool function. This function can be used to convert values to booleans.

- set(attributes["my.bool"], Bool("true"))

Link to tracking issue

Closes #44770

Testing

Added new unit and e2e tests.

Documentation

Added function doc.

[iblancasa]

Maybe this should be false? Like in Python

[edmocosta]

That's a great question, I think I'd stick to the strconv.ParseBool approach (used by ottl.BoolLikeGetter) and continue to treat empty strings as errors instead of false. It's also consistent with other type conversions we support such as Int and Double, that also relies on the strconv package for that.

[iblancasa]

Should we also test an empty slice?

[edmocosta]

Thank you for working on this @danelson, it looks good, just a few suggestions.

[edmocosta]

Suggested change

	},
	},
	{
	name: "string t",
	value: "t",
	expected: true,
	},
	{
	name: "string f",
	value: "f",
	expected: false,
	},
	{
	name: "string T",
	value: "T",
	expected: true,
	},
	{
	name: "string F",
	value: "F",
	expected: false,
	},

Those are also valid string values.

[edmocosta]

Suggested change

	The returned type is bool.
	The returned type is `bool`.

[edmocosta]

Suggested change

	The input `value` types:
	The accepted input `value` types are:

[edmocosta]

Suggested change

	If `value` is another type or parsing failed nil is always returned.
	If `value` is another type or parsing failed, `nil` is always returned.

[edmocosta]

Suggested change

	- bool. Keeps value as is.
	- float64. Zero is false, any non-zero value is true.
	- int64. Zero is false, any non-zero value is true.
	- string. Tries to parse an bool from string. If it fails then nil will be returned. The following are some valid inputs that are parsed as true or false:
	| Input | Output |
	| --- | --- |
	| `"true"` | `true` |
	| `"false"` | `false` |
	| `"True"` | `true` |
	| `"False"` | `false` |
	| `"TRUE"` | `true` |
	| `"FALSE"` | `false` |
	| `"1"` | `true` |
	| `"0"` | `false` |
	- `bool`: Returns the value without changes.
	- `float64`: Returns `true` if non-zero, otherwise `false`.
	- `int64`: Returns `true` if non-zero, otherwise `false`.
	- `string`: Tries to parse a boolean from the string. It returns `true` for "1", "t", "T", "true", "TRUE", or "True"; returns `false` for "0", "f", "F", "false", "FALSE" or "False".
	- `nil`: Returns `nil`.