Merge branch 'issue-template-problem-validation' into 'master'

Added Problem Validation issue template

See merge request gitlab-org/gitlab!16595

.gitlab/issue_templates/Problem_Validation.md

+## Problem Statement
+
+<!-- What is the problem we hope to validate and solve? -->
+
+## Reach
+
+<!-- Please describe who suffers from this problem. Consider referring to our personas, which are described at https://about.gitlab.com/handbook/marketing/product-marketing/roles-personas/ -->
+
+<!-- Please also quantify the problem's reach using the following values, considering an aggregate across GitLab.com and self-managed:
+
+10.0 = Impacts the vast majority (~80% or greater) of our users, prospects, or customers.
+6.0 = Impacts a large percentage (~50% to ~80%) of the above.
+3.0 = Significant reach (~25% to ~50%).
+1.5 = Small reach (~5% to ~25%).
+0.5 = Minimal reach (Less than ~5%). -->
+
+## Impact
+
+<!-- How do we positively impact the users above and GitLab's business by solving this problem? Please describe briefly, and provide a numerical assessment:
+
+3.0 = Massive impact
+2.0 = High impact
+1.0 = Medium impact
+0.5 = Low impact
+0.25 = Minimal impact -->
+
+## Confidence
+
+<!-- How do we know this is a problem? Please provide and link to any supporting information (e.g. data, customer verbatims) and use this basis to provide a numerical assessment on our confidence level in this problem's severity: 
+
+100% = High confidence
+80% = Medium confidence
+50% = Low confidence -->
+
+## Effort
+
+<!-- How much effort do we think it will be to solve this problem? Please include all counterparts (Product, UX, Engineering, etc) in your assessment and quantify the number of person-months needed to dedicate to the effort. 
+
+For example, if the solution will take a product manager, designer, and engineer two weeks of effort - you may quantify this as 1.5 (based on 0.5 months x 3 people). -->
+
+/label ~"workflow::problem backlog"