## Bug description

The grouped-by-month view in charts is hella confusing. The x-axis shows a date that does not reflect the value on the y-axis.

1. the y-axis shows the number for the END of the month
2. the x-axis reads as "beginning of the month"

![CleanShot 2024-02-05 at 10 23 30@2x](https://github.com/PostHog/posthog/assets/35429197/d78df745-8319-4b78-95fa-d96f18aee357)

### Comparison with daily grouping

Compare the "group by month" view with "group by day". The x-axis labeling aligns with the y-axis values. 

![CleanShot 2024-02-05 at 10 29 20@2x](https://github.com/PostHog/posthog/assets/35429197/998825fa-7406-4214-8310-8f173980f80c)


## How to reproduce

1. Group a chart by month 
2. select "unique events"

## Proposal 

### 1. easy fix - remove the "1." from the labelling

- will still confuse readers with "is this the beginning or end of the month"

![CleanShot 2024-02-05 at 10 23 30@2x](https://github.com/PostHog/posthog/assets/35429197/1a0ae6d4-0e02-4b32-86ab-7b0e069655ed)

### 2. correct fix - show end of month

- removes ambiguity from "is that the beginning or end of month"
- harder to implement because months have different end days

![CleanShot 2024-02-05 at 10 23 30@2x](https://github.com/PostHog/posthog/assets/35429197/61226346-7f97-4bcd-87bf-53fc83c75245)


cc @jannesblobel
posthog/hogql_queries/insights/lifecycle_query_runner.py
self, day: Optional[str] = None, status: Optional[str] = None
    ) -> ast.SelectQuery | ast.SelectUnionQuery:
        with self.timings.measure("persons_query"):
            exprs = []
            if day is not None:
                exprs.append(
                    ast.CompareOperation(
                        op=ast.CompareOperationOp.Eq,
                        left=ast.Field(chain=["start_of_period"]),
                        right=self.query_date_range.date_to_start_of_interval_hogql(
                            ast.Call(name="toDateTime", args=[ast.Constant(value=day)])
                        ),
                    )
                )
            if status is not None:
                exprs.append(
                    ast.CompareOperation(
                        op=ast.CompareOperationOp.Eq,
                        left=ast.Field(chain=["status"]),
                        right=ast.Constant(value=status),
                    )
                )
            return parse_select(
                "SELECT DISTINCT person_id FROM {events_query} WHERE {where}",
                placeholders={
                    "events_query": self.events_query,
                    "where": ast.And(exprs=exprs) if len(exprs) > 0 else ast.Constant(value=1),
                },
            )
    def to_actors_query_options(self) -> InsightActorsQueryOptionsResponse: