some components (like Modal) do not work correctly in V45 of salesforce

[ArunChockalingam]

Some components like modal do not work correctly anymore starting with V45 of salesforce as salesforce has deprecated the slds classes that are being used.

Reference: https://archive-2_7_0.lightningdesignsystem.com/release-notes/

Deprecated SLDS classes:

The following features are being marked as deprecated in this release and will be removed in three releases:

• Lookups have been updated. Version 1.0.0 has been deprecated. Will continue to work but please update to new markup - Lookup component
• Page headers have been updated. Version 1.0.0 has been deprecated. Will continue to work but please update to new markup - Page Header component
• .slds-toggle-visibility is no longer needed in button-groups. The final button will no longer disappear if it is a button-icon, but instead will gray down like a normal disabled button.
• .slds-button-space-left is no longer supported. Please use spacing utilities instead.
• .slds-button_icon-bare is no longer needed. Please use .slds-button_icon instead.
• .slds-card_empty is no longer needed. Please use .slds-text-align_center utility class instead.
• .slds-button inside of .slds-is-sortable is no longer needed. The entire cell is hyperlinked now, no need for the button.
• .slds-form-element__helper is no longer supported.
• .slds-input__icon no longer supports a color by default. Please use .slds-icon-text-default on the SVG icon instead.
• .slds-icon__container is no longer supported. Please use .slds-icon_container instead.
• .slds-icon-custom-XX is no longer supported. Please use .slds-icon-custom-customXX instead.
• .slds-dropdown_nubbin-top is no longer supported. Please use .slds-nubbin_top instead.
• .slds-has-icon_left, .slds-has-icon_right, and .slds-has-icon_left-right within dropdowns are no longer needed. Icons can be placed within the flow of a .slds-dropdown__item.
• .slds-modal-backdrop is no longer supported. Please use .slds-backdrop instead.
• .slds-notify-container is no longer supported. Please use .slds-notify_container instead.
• .slds-pill-container and .slds-pill__container are no longer supported. Please use .slds-pill_container instead.
• .slds-pill__container_bare is no longer supported. Please use .slds-pill_container_bare instead.
• .slds-tabs__item is no longer supported. Please use specific element selectors instead, such as .slds-tabs_default__item or .slds-tabs_scoped__item.
• .slds-tooltip and .slds-tooltip__body are no longer supported. Please use .slds-popover and .slds-popover__body instead.
• .slds-tree-container is no longer supported, please use .slds-tree_container instead.
• .slds-col-rule_left, .slds-col-rule_right, .slds-col-rule_top, and .slds-col-rule_bottom are no longer supported. Please use .slds-col_rule-left, .slds-col_rule-right, .slds-col_rule-top, and .slds-col_rule-bottom instead.
• .slds-nowrap_small, .slds-nowrap_medium, and .slds-nowrap_large are no longer supported. Please use .slds-small-nowrap, .slds-medium-nowrap, and .slds-large-nowrap instead.
• .slds-align-content-center is no longer supported. Please use .slds-align_absolute-center instead.
• .slds-has-dividers is no longer supported. Please use .slds-has-dividers_{position} instead.
• .slds-has-divider is no longer supported. Please use .slds-has-divider_{position} instead.
• .slds-has-cards is no longer supported. Please use .slds-has-divider_around instead.
• .slds-has-cards_space is no longer supported. Please use .slds-has-divider_around-space instead.
• .slds-section-title is no longer supported. Please use .slds-section__title instead.
• .slds-collapsed is no longer supported. Please use .slds-is-collapsed instead.
• .slds-expanded is no longer supported. Please use .slds-is-expanded instead.
• The rule that hides the close button in Notification Prompt .slds-modal_prompt .slds-modal__close is no longer needed as the HTML should be removed. Please remove the button from the dialog header.